The microsaver lock head features the patented t bar locking mechanism the t bar provides a tight fit with the kensington security slot a rubber bumper ensures a snug fit between the lock and the security slot and protects your hardware a further deterrent is the tamper evident feature when a kensington microsaver lock is tampered with it locks itself down and can even trap foreign keys all kensington locks are built to exacting engineering standards this lock is rated as safe pro a r