A variety of unlocking options: password, card swipe and mobile APP. Electronic lock & mechanical 2 in 1: Comes with backup mechanical keys, more durable. Compatible with Alexa and good home via bluetooth gateway. The lock also can be remotely unlocked, checked history, time attendance and so on. Powered by 4pcs AA Alkaline batteries.Specifications: Access method: APP, passcode, card, mechanical key App: TT lock System Compatibility: IOS / Andriod Work Voltage: 4.6-6V Power Supply: 4pcs AA batteries. This item is in the category "Home & Garden\Home Improvement\Building & Hardware\Doors & Door Hardware\Door Locks & Lock Mechanisms". The seller is "easyshopping20142014" and is located in this country: CN. This item can be shipped worldwide.