"The Patagonia Triolet Jacket is built for technical routes, exposed ridgelines, and summit pushes where waterproof-breathable protection has to work without compromise. The 3-layer GORE-TEX ePE Performance shell bonds the membrane directly to the face fabric and tricot backer, eliminating the loose liner that traps heat and adds bulk in a 2-layer construction. The RECCO reflector adds rescue-detection capability that matters most when committing terrain puts a party beyond easy reach. What Our Gearhead® Experts Are Saying:""I trust this shell on routes where the weather window can close fast. The fully sealed seams and GORE-TEX ePE membrane keep rain and wind out without making the jacket feel like a sauna on the approach."""