Calling it a onesie doesn't do the Flight Suit GTX justice. Its 2L GORE-TEX stretch fabric design ensures ease of movement on the mountain with a waterproof guarantee that only GORE can provide. Eco-friendly PrimaLoft Insulation and a sherpa collar provide incredible Insulation for the coldest days, while the underarm vents and side zippers keep you from overheating. An internal suspender system allows you to conveniently take just the top of the Flight Suit off for additional comfort in the lodge or when celebrating a successful mission at apr?s ski.