This handy tool is designed for measuring and verifying Gripple cable sizes in the field. Slide the cable into the appropriate hole to determine what Gripple cable size you have: No.1 (1/16 in.), No.2 (5/64 in.), No.3 (1/8 in.), No.4 (3/16 in.), or No.5 (1/4 in.). Use on a job site to ensure that the correct Gripple cable size is being used with the correct size fastener. Add it's a key chain! Great giveaway for contractors, distributors, and installers!