Don't ruin great layers with average undies. Our best-selling lightweight Altitude Merino Underwear now come in briefs! Rest assured, they're every bit as soft, lightweight, warm and comfortable as the rest of our high-performance thermal layers, offering superior performance to keep you warm and comfortable when you need it the most. Tag-free labels, flatlock stitching and a flexible, ultra-soft ioMerino elasticated waistband help eliminate chafe and bulk and maximize comfort and a self-fabric fly adds both comfort and function. Say goodbye to ordinary undies, and hello to the new Men's Altitude Merino Briefs. SIZE & FIT True to size. Model wears size small in black and rust. Model specs - height 173, chest 99cm, waist 76cm.Model wears size medium in forest marle and moroccan blue. Model specs - height 181cm, chest 103cm, waist 81cm (32 inch). Normally wears 32 inch pant, 10-11 size shoe. Self fabric real fly. Mid rise. Designed to fit perfectly under our other layers. Size Guide. BEST FOR Everything!