Trend Guide Bushes can be attached to the base of the Router. They are designed to follow the contours of a template. Guide bush guides the router when using a template. Fits directly to Trend T3,T4,T5,T5 MK2, T9,T10 and T11, and some other light duty routers. Will fit other makes when used with GB/5, GB/PLATE or UNIBASE Sub-base. Outside diameter 16mm Inside diameter 14mm Projection from plate 10mm