Our Commercial Tablet Stand has two locks on the back of the tablet holder.  One is a slide lever to lock and unlock the arms of the tablet holder and the other is a push button antitheft lock. If the push button lock is pushed in, the slide lever will be locked. You will need to unlock the push button lock with the tubular provided keys.  If you have lost your keys, we offer them in this set: Keys 35429 and wrench