Tandem Active Ankle AS1 Ankle Brace The AS1 Active Ankle Brace is designed for mild-to-moderate ankle sprains with non-stretch straps that lock in the heel, imitating the effects of a tape job. 840 denier nylon shell is lined with neoprene to offer maximum comfort and fit. The shell is coated with a double layer of Teflon to prevent abrasion related wear. Circumferential strap stabilizes the brace to prevent unwanted slippage. Fits left or right ankle. One brace per pack.