Big Horn Brass Router Template Guide I.D. 11/32 in. O.D. 7/16 in. is a precision tool designed to provide controlled and accurate cuts when using a router with a pattern or template. This guide easily attaches to the router base, maintaining a consistent distance between the router bit and the edge of your template, allowing for smooth and precise routing into your workpiece. It serves as a reliable for Porter Cable 42027, ensuring compatibility and performance for your routing projects. Model Number: 19661