Men’s Thermal Long Underwear Set Just $9.99 on Amazon (Reg. $24)

By Cara | Staff Writer

Sep 24, 2026 @ 12:15 PM MDT

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a man in a thermal base layer on a sofa drinking coffee

Through September 30th, pop on over to Amazon where you can score these Roadbox Men’s Thermal Long Underwear Sets for just $9.99 (regularly $23.99) when you use the promo code UXD0M3N1 at checkout.

Men’s Thermal Long Underwear 2-Piece Set $19.99 (reg. $23.99) – 13 colors
Use promo code UXD0M3N1
Final cost $9.99!

*Note that the promo code does not stack with any other coupons or offers.

These base layer sets are thin and stretchy, making them perfect for layering without adding extra bulk while still keeping you warm and toasty on the coldest days.

They get great reviews, too! Here is just one…

Not so thick; size was perfect and comfortable, and yes, they really work. Went to NY for Christmas, and it was 39° freezing and snowing; these helped ease the leg coldness. We walked a lot; thanks to this set, I kept warm underneath.

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About the writer:

Cara is a deal-loving writer with over two decades of experience across a variety of publications and digital platforms. She now creates fun, high-performing deal content readers love to click at Hip2Save.