Brake Roller / Speed Controller Dia.:80mm,92mm,120mm Material: nylon ... We are one of the earliest and most professional Brake Roller manufacturers in China.Brake Roller Series: Dia.:80mm, 92mm, 120mm, TandemMaterial ... video on: http://www.youtube.com/watch?v=Z7gWxgreP08 Brake roller(also called speed control roller), is very important ... need samples! Speed Controller in Gravity Pallet Rack Brake Roller