GUIDE BUSH
The guide bush [1] is usually supplied with the router [2] from new. They come in different shapes and sizes, but their function is the always the same.
It is fixed to the base plate [3] of the router so that the short tube bit is left protruding.
This short tube then locates into the slot in the template, as you machine, the guide bush slides along the edge of the template slot. This ensures that you cut exactly where you are supposed to, and you will cut the perfect joint.
