THIS IS AN ISCAR ETM CATI 50-MB50 MODULAR TOOL HOLDER DESIGNED FOR TOOLING APPLICATIONS. KEY SPECIFICATIONS INCLUDE A CAT 50 HOLDER TYPE, A 3-1/8IN BODY DIAMETER, AND A 1.67” BORE DIAMETER. THE OVERALL LENGTH (OAL) IS 6-3/8IN WITHOUT THE BUTTON AND 8-1/4IN WITH THE BUTTON, WITH A PROJECTION OF 2-1/4IN.