Plastic replacement thumb lock used in various hatches made by B&B Molders. The hole for this lock can be no larger than 7/8" I.D. and at least 3/4" I.D. Press in lock, which uses built-in spring-loaded tabs to hold the lock in place. The blade is 3/4" wide by 1-1/2" long and is non-removable. Lifetime warranty.