Park Tool SG-6 Threadless Fork Saw Guide
Designed to ensure a straight, clean cut on threadless forks, the SG-6 fits 1", 1-1/8" and 1-1/4" forks. A must for use with threadless fork systems. Simply slide the guide onto any threadless fork, clamp it down, and cut using the narrow cutting slot. Heat treated for long life.
This is something I don't use a lot but when you need it, it does the job right. Great to have in the tool box.