STOP & LOCK is designed to lock your brake in place so it cannot engage when not in use. Prevents accidental braking. Stop & Lock can be used with all previously purchased instructor brakes.
Check to see if your base plate has a secondary hole drilled into the sides of the base.This hole is where the locking clevis pin goes to lock the brake down.
If your brake does not have this hole you, will need to drill a 1/4 inch hole, to use the Stop & LOCK. The drilling into aluminum is quite easy because aluminum is so pliable.
Stop & Lock will also work without using the locking clevis pin. Just slide the aluminum wedge under the brake arm to secure the brake.