• • Important Note• •  Please Read: If your installation requires a 2 3/4" Backset Latch you must request it at time of purchase or you will receive a 2 3/8" Backset latch with your order.• • This lock is a stand alone ID card access door lock. It is designed for all kinds of doors including residential homes, apartments, warehouses, airports, and office buildings. It fits most predrilled 2-3/8" or 2-3/4" backset knob-lock doors. Programming cards is very easy and takes only a few minutes. Programming cards is done by lock, no extra equipment needed. One card can be programmed to many locks. A card also can be deleted from locks. One lock can be programmed for up to 500 cards. Works with most 125khz frequency RFID cards (cards sold seperately).The lock will mechanically automatically lock itself when the door is closed. From outside, you can turn the handle but the door will be locked. The only way to unlock the door from outside is by key or cards. From inside, just turn the handle and unlock the door. It works like a regular lock, no key or cards needed.Main Features:Novel and sleek appearanceSimple installation instead of ball style mechanical lockUse standby key to open lock in case of emergencyAlert for wrong cardUp-to-date material for stable and durable performanceTechnical parameters:Suitable for door thickness: 35~50mm_ and standard 2 3/8" backset (2 3/4" backset is available upon request)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 timesProduct Dimensions:Outside:Length: 7 7/8" Width: 2 1/2" Depth: 1" Latch center to top: 4 1/2"Latch center to bottom: 3 3/8"Inside:Length: 4" Width: 2 1/4" Depth: 3/8" Latch center to top: 2 1/4"Latch center to bottom: 1 3/4"Package Content:One Keyless Electronic RFID MID300 right hand lock retail boxNote:ID cards are sold separatelyHow to select the correct lock: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 the edge of the door: one size is 2-3/8" the other size is 2-3/4 ".