The Rab Argon Pants are filled with 800 fill power European goose down to provide extra warmth for those cold climbing days, harsh bivy nights or for a warm pant around basecamp. 800FP R.D.S Certified European Goose Down (160g/ 5.6oz size L) PertexA(R) Quantum inner PertexA(R) Quantum outer fabric RabA(R) Fluorocarbon free Hydrophobic Down developed in conjunction with NikwaxA(R) Stitch-through midi-baffles Belted waistband (removable) with snap closure YKKA(R) VISLONA(R) 2-way front fly zip with 2 insulated zip baffles Elasticated stretch hem Stuff sack Fit: Regular (designed to be worn over a baselayer pant) RAB Men&';s Apparel