Specification: Securely holds 1/4 – 5/8 square diameter tool bits. Interchangeable with Dorian, Aloris, & Phase II BXA series tool posts. For use with BXA tool posts 250-200 or 250-222. Precision ground and hardened. Completely sealed for maintenance free operation. Turning and facing tools can be locked together (saving time and labor when changing operations). Feature: The Product Has Passed Strict Quality Testing. Durable And Easy To Install And Replace. Cost-effective, Good After-sales Service.