METechs - Keyless Electronic RFID Card Reader Door Lock MID300 Left Hand Suitable for door thickness: 35~50mm and standard 2 3/8" backset (2 3/4" backset is available at time of purchase upon REQUEST). 500 RFID can be programmed to the lock; Programming RFID is done by lock, no extra equipment is required. Service life of battery: approx. 20,000 times (up to two years), Low battery alert. Solid structure design for security and durability, Tamper-proof error function, vandal-resistant lever design. Easy installation, only need a Philips screw driver to install on predrilled door. One year METech warranty and lifetime tech support Novel and sleek appearance Simple installation instead of ball style mechanical lock Use standby key to open lock in case of emergency Alert for wrong card Up-to-date material for stable and durable performance Suitable for door thickness: 1 3/8&#034; to 2&#034; (35~50mm) Standard 2 3/8&#034; backset <span class="a-text-bold"> (<span class="a-text-italic"><u>2 3/4&#034; backset is available at time of purchase upon REQUEST)</u></span></span> Requires 4 AA 1.5V alkaline batteries (included) Service life of battery: approx. 20,000 times (up to two years) It will alarm for low power supply and can still open for approx. 50 times Length: 7 7/8&#034; Width: 2 1/2&#034; Depth: 1&#034; Latch center to top: 4 1/2&#034; Latch center to bottom: 3 3/8&#034; Length: 4&#034; Width: 2 1/4&#034; Depth: 3/8&#034; Latch center to top: 2 1/4&#034; Latch center to bottom: 1 3/4&#034; One Keyless Electronic RFID MID300 left hand lock retail box ID cards are sold separately It comes with standard 2 3/8&#034; backset (Let us know If you need 2 3/4&#034; backset when you place order) Left-hand or right-hand lock: when looking at the door from OUTSIDE, hinges on left indicate a left hand door, hinges on right indicate a right hand door. There are two popular backset sizes for pre-drilled doors. Measure from the handle center to edge of door: standard size is 2-3/8&#034;, the other size is 2-3/4 &#034;, available by request.