Features The product is a set of two groups, namely active roller frame and passive roller frame. Active and passive roller frame has 4 rollers with the structure of inner iron core and outer rubber which is durable and without vibration when using. The running of active roller frame is driven by both reducers synchronously, by means of the mechanisms of adjusting motor, reduction box and controller etc. it can make the running speed of work piece up to 0.1-1m/min.http://www.bending-machine-china.com/pid11407398/light+ZT+series+self-adjustable+roller+frame.htm