1.master key lock 2.no battery master key lock 3.password master key lock 4.mechanical master key lock 5.master key lock mechanical master key lock with numbers                       master key lock advantages:  1. Master (over-ride) key provided to recall forgotten personal code 2. Locker thickness required: 0.7mm~1.2mm 3.Users can set up their own passwords, up to 10,000 combinations provided 4.Dual mechanism: digits combination and master key for emergency opening 5.no battery master key lock,  mechanical master key lock   master key lock detail pictures Model: C500 VersionColor: Silver WhiteMaterial: ABS Plastic  master key lock Convenient installationJust get the lock right intothe hole, press it and thenmake work done   How to set the combination Rotate the four dials to your desired combination and then turn the knob.  ***Remember to scramble the numbers after locking master key lock Certificate CE, FCC approved  master key lock suitable for cabinet, drawer etcCombination lock is suitable for use on a wide range of metal and plastic lockersand cabinets.  The mechanism has 10,000 combinations and the user selects their own four-digit code