Park Tool has long provided some of the best cutting and machining tools in the bicycle industry. Their 690 Cutting Facers reflect their commitment to maintaining this high level of quality. Please read below for use and compatibility information specific to each size cutter: - 45mm (690): The 690 cutting facer is used on the HTR-1, HTR-1B, BFS-1, and BTS-1 cutting and facing tools. The facer has an outside diameter of approximately 45mm. - 57mm (690XL): The 690-XL is a larger version of the 690 facer for the HTR-1 Head Tube Reamer and Facer. It has a nominal outside diameter of 57mm. It may be used in conjunction with the 788 reamer. It is also used with the 767 Pilot or the 768 Pilot to face only the large diameter headtubes used with, "low profile," ZS-type headsets. - 65mm (690-XXL): The 690-XXL faces large headtubes. It has a nominal outside diameter of 65mm. Use the 690-XXL facer with the 750.2 Centering Cone Adaptor and 789 Reamer or 790 Pilot when facing head tubes with internal diameters of 55.95-55.90mm.