This listing is for a size 10 woman's Marker red & black nylon one-piece snow suit with a nylon lining.
It's a vintage style from the 1980's, I'd guess. Measures about 25 inches armpit to armpit with an inseam of 30 inches.
Size 10 would insinuate it's a woman's cut, but it looks unisex to me. Based on the measurements, a man could wear it too.