The Unibase enables routers with non-standard guide bush fittings to accept the range of Trend guide bushes, Will fit directly to most routers.Line-up pin used with a 16mm plastic bush to ensure concentricity of the cutter to the guide bush when fitting the sub-base. Suits collet sizes 1/4 inch, 8mm, 12mm and 1/2 inch.Instructions for fittingThe line-up pin fit into the collet and is plunged through the router base. The line-up bush is fitted into the Unibase and secured. This is then placed over the line-up pin and rotated in order to line up the fixing holes. The Unibase screws are tightened and then the line-up bush can be replaced with any choice of Trend guide bushes. These range from 10mm up to 30mm (GB10 - GB32). For larger diameter cutters a 40mm guide bush (GB40) is available. Diameter=170 mm Thickness=8 mm. Includes 2 x Line-up pins|1 x Guide bush|1 x Fixing screw pack.