Body Glove .5mm Insotherm Flatlock Fullsuit, Medium Should fit snug, but not too tight .5mm Titanium insotherm thoughout flatlock seams anatomically cut Great layering piece for colder conditions great protection from Jelly fish Combination of SCS Titanium, open cell, and Nylon. 30% more warmth than standard Neoprene0.5MM titanium throughout. Reflective material traps heat inside the suitPolypropylene underarm gussetsFlatlock stitching prevents rashingAdjustable velcro collar