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Equinoxx K2 Dyna-Thermal - Cold-Weather Thermal Protection + Full Mobility

Equinoxx K2 Dyna-Thermal - Cold-Weather Thermal Protection + Full Mobility

Equinoxx K2 Dyna-Thermal -

K2 Dyna-Thermal wears like a shirt yet protects like a coat. Enjoy harsh-weather protection as well as freedom of movement for any outdoor activity—from construction work and motorcycle riding, to hunting, fishing, hiking, skiing and golf.

K2 Dyna-Thermal wears like a shirt yet protects like a coat. Enjoy harsh-weather protection as well as freedom of movement for any outdoor activity—from construction work and motorcycle riding, to hunting, fishing, hiking, skiing and golf.

Original price $ 125.00 - Original price $ 355.00
Original price
$ 125.00
$ 125.00 - $ 355.00
Current price $ 125.00
Quantity: 1-Pack
Size: S
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free shipping on domestic orders over $100

Domestic + International Shipping


Domestic First Class Package Shipping normally ships for receipt within 5-10 business days. Saturdays, Sundays and holidays are not considered business days. Expect an extended delivery date when:

  • Merchandise requires personalization
  • Merchandise is shipped direct from the manufacturer
  • Merchandise is of an irregular size or weight 
  • Merchandise is on back order from the manufacturer
  • Shipment is destined for a U.S. Territory or Possession
  • USPS is experiencing delays due to unexpected circumstances 

If you required more trackable and quick delivery, please select UPS Ground. Extra charge will apply. 

In the case of a backorder, all items may be delayed until all items are available for shipment.

We recommends providing a street address for shipping since using a P.O. Box address may result in a delay. Deliveries to APO/FPO and P.O. Boxes will be shipped via United States Postal Service at Standard rates. Select Standard Shipping at checkout. Allow for extended delivery times.


First Class International Package is the most affordable shipping option but please be aware that it may take between 4 - 10 weeks for delivery depending on your location. 

There may be delays due to Increased volume and carrier’s reduced capabilities to handle packages related to COVID-19. Please allow more time in consideration of current situation. 

All prices on our site are in US dollars. Your credit card company will bill you with your local currency at the current exchange rate.

When ordering outside of United States of America, the recipient is responsible for assuring the product can be legally imported to the destination country.

The recipient is the importer of record and must comply with all laws and regulations of the destination country. The recipient of an international shipment may be subject to import taxes, customs duties and fees, which are imposed once a shipment reaches the recipient's country. Additional charges for customs clearance must be fulfilled by the recipient. 221B Tactical has no control over these charges, nor can predict what they may be.

Customs, duties, and taxes are non-refundable: so a shipment that is refused because of unexpected import fees, the cost of the original shipping and any return shipping charges will not be refunded. Customs policies vary widely from country to country; you should contact your local customs office for more information. When customs clearance procedures are required, it can cause delays beyond our original delivery estimates.

To avoid a delay in receiving your order from customs, we strongly suggest:

  • Providing a phone number where you can be reached by customs when your product arrives. This phone number will be listed on the commercial invoice so customs can reach you to clear your order.
  • Please do not refuse a shipment or ignore requests from carriers regarding duty and/or tax liability charges. Be aware that most carriers will hold a shipment for 5 days after arrival in your country before they return it to the sender.

We do not refund original shipping charges for goods that are refused for delivery at customs.

If you have any shipping questions regarding your order, please contact us:

free returns

Returns & Exchanges

Return Policy

221B Tactical has a 30-day returns and exchanges policy except for Body Armor products and Watches.  You may return your merchandise to 221B Tactical within 30 days upon the receipt of your product. Refunds will be applied to the original credit card used at the time of purchase.

Clothing/Apparel can not be returned or exchanged after they have been worn for any reason other than fitting. They can not be returned or exchanged after washing. If you find that size does not fit, please do not wear them again and contact us immediately for return or exchange. Underwear can not be returned for any reason and are Final Sale.

Postage will be refunded on returns due to defective merchandise or an error in shipping.  Postage will not be refunded on returns or requests for size exchanges.  In the event that the style being returned is no longer available for exchange, a product of equal value may be offered. 

221B Tactical will only honor returns on orders placed directly with  

221B Tactical will not honor returns on merchandise purchased at outside retail locations.  No returns or exchanges will be accepted for products purchased from unauthorized sellers. Please contact that seller directly.  

Return and exchange shipping charges will only be covered by 221B Tactical in the event of an exchange of a defective product or a shipping error.

Please be sure to follow washing and handling instructions carefully.  We at 221B Tactical take great care to offer you the best quality products.  We ask that you please do your part to follow the washing instructions carefully to protect your investment and to avoid voiding your warranty. Thank you. 


To Make a Return or Exchange

1) Email us at and explain the reason for exchange or return to obtain authorization for return or exchange.
2) Please put your order number as attention.

We recommend using UPS to ship your return.  If sending via regular mail we recommend insuring your parcel.  Mail returns to:

Attn: Order#
221B Tactical
43 West 33rd Street
Room 501 
New York NY 10001

Thank you!


Equinoxx K2 Dyna-Thermal is a shirt that'll keep you warm and comfortable in the harshest weather. It retains body heat, blocks wind, and resists rain. It's breathable, so you don’t overheat after coming in out of the cold. Thanks to its special material and construction, it also gives you the flexibility and freedom of movement to perform at your best at work or play.

"All my coworkers had on the bulky carhartt jackets with hoodies underneath and whatever else. They couldn’t believe I was out in that climate with no jacket....This is perfect for construction and doesn’t restrict movement at all."  
—Mario Jimenez (Stage 3 review, Jan. 21, 2022)

K2 offers all the same features and benefits of our popular Equinoxx Stage 3 Thermal, a base layer for police officers and anyone wearing body armor in cold weather. But unlike Stage 3, which doesn't fully protect the mid-section (covered by body armor), K2 provides full 360-degrees thermal protection, from just below the waist to over the neck, just below the chin. It's all you need.


Ideal for All Kinds of Outdoor Activities

K2 is ideal for anyone who works outdoors and could benefit from freedom of movement as well as protection from cold, windy, and wet weather—from postal workers and courier drivers to traffic and school crossing guards; from cable installers and linesmen to construction and oil rig workers.

"I stay warm without having to wear a coat with temperatures ranging between 10-30 degrees Fahrenheit. It’s light weight and doesn’t hinder my mobility at all."  
—Joshua N. (Stage 3 review, Dec. 10, 2020)

K2 is also great for any kind of outdoor recreational activity, such as hunting, fishing, hiking, camping, golf, skiing, ice skating, bird watching....You name it! It's also good for motorcycle riders who need to block the cold wind.

Police and security personnel who already have our Stage 3 as a body armor base layer may want K2 for their cold-weather leisure activities.

"Amazing. This is the only thing to ever work as advertised. I can finally work during the winter and not dread how cold I will be all season." —Edward D. (Stage 3 review, Dec. 17, 2017)


Innovative Materials & Construction

The K2 Dyna-Thermal is soft, stretchy and not bulky, promoting superior comfort and mobility. Yet it's constructed with a state-of-the-art heat-pressed, triple-layer fabric that provides highly effective thermal protection. The top layer is a stretchy polyurethane fabric. The middle layer resists water and wind. And the inner layer, which touches your body, is a soft, grid-thermal fleece.

The "Grid" design structure of the base layer’s fleece inner liner is the latest technology to reduce fabric weight while increasing warmth and compress-ability. This form of construction enhances both wicking efficiency and breath-ability by generating channels of targeted touch points that absorb and diffuse moisture vapor for faster evaporation.

"I didn't have to wear a coat all winter, which is amazing since the month of March here in Montana saw an average temp of -1 degrees. The insulated sleeves were amazing, and easily kept my arms warm no matter the weather."—J Wolf (Stage 3 review, Oct. 3, 2019)



  • Full 360° Grid Thermal Protection
  • Maximum Body Heat Retention
  • Temperature Rating: Sub 15° F / -9.45° C
  • Superior Mobility
  • Water Resistant
  • Wind Blocking
  • Breathable, for Coming In Out of the Cold
  • Regular Fit
  • Extended Compression Sleeve Cuffs
  • Extended Torso Length - Stays Tucked In
  • Mock Neck Design



  • Machine wash cold
  • Hang dry (preferred) or tumble dry (low)
  • Choose your usual shirt-size as you would with any shirt.  Considering these are designed to be form-fitting, we recommend selecting the larger size if in between sizes.






Customer Reviews

Based on 13 reviews

Fits awkwardly is warm would go with under-armor for this money

Have you tried it outdoors yet in various activities? Once you get used to putting it on and off, we hope you'll see the benefits it can offer to you. Thank you. - Brad @ 221B


It was too small 😡


Love mine. Best investment for camping.


Super nice out layer garment feels good keeps you warm on those cold days. It fits a tad snug I usually wear a large glad I ordered the xl or it would have been a struggle to get on only complaint I have and it’s small it’s tight against the arm pit area. All around great garment.

Joe Gambardella
Poor I’m xl and did not fit

1star not true to size I’m xl and the xl was to small

Sounds like you need an XXL. Please email and our support team can help you.