This is the Park Tool CRS-1 Crown Race Setting System. The CRS-1 offers a six inserts with to install the fork crown race. The bearing surface is spared a direct hit by using different inserts to ensure proper fit on the race. Choose the correct insert then slide the tube over the fork tube and into the top end of the insert. Using a hammer, tap firmly on the end cap of the tube and seat the race into its proper place safely and accurately. The CRS-1 set includes one universal setting tube, three 1" inserts, and three 1-1/8" inserts. The CRS-1 will work on forks of 340mm column length or less. For oversized column in 1-1/4" or 1-1/2" use the CRS-15 Crown Race Setter. SHIS terminology: The CRS-1 services in SHIS sizes 26, 27, 30.