The Kinklab Neoprene Cuffs are comfortable, inexpensive as far as cuffs go, and sturdy. The washable cuffs close with velcro and will fit up for a 10" (25 cm) wrist or ankle. The strong hardware is nickel-free and on a swivel so it won't get twisted or tangled during play. The neoprene cuffs are lined with soft spandex and have nylon webbing around the velcro to add strength.