Reece MCB Toggle Lock simply fits over the MCB toggle using a small flat screw driver, tighten the internal grub screw to secure the CB12 onto the toggle. It is possibly the simplest yet most versatile MCB lockout in our range. Gives a low profile solution allowing the panel door to close with padlock fitted. Once tight and secure, insert your padlock which blocks access to the grub screw so the device cannot be removed or toggle operated until the lock is removed.