Calumet CK9001 Sliding Adapter Plate with 1/4" and 3/8" Camera Screws and a Built-in Spring-loaded Camera Alignment Pin The rubber pads grip your equipment to prevent shifting. Includes both 1/4"-20 and 3/8"-16 camera screws and a built-in, spring-loaded, camera alignment pin. For use with the Calumet CK9007 quick-release video head adapter.