August Wi-Fi, (4th Generation) Smart Lock ? Fits Your Existing Deadbolt in Minutes, Matte Black, UPGRADE YOUR EXISTING DEADBOLT: August smart locks fit on the inside of your door, making your regular deadbolt smarter, more secure and way more convenient. Keep your keys just in case (but you won’t need them)., GRANT ACCESS WITH THE AUGUST APP: Forget key copying. Quickly and easily share permanent, scheduled or temporary access to your home with friends, family and other people you trust, and never put a key under the doormat again., EASY TO INSTALL ON ANY DOOR: Even if you’re not so handy, installation only takes about 10 minutes. August locks fit perfectly over most single cylinder deadbolts and aren't much bigger than your original thumbturn., AUTO-LOCKS AND UNLOCKS: August Wi-Fi Smart Lock is able to Auto-Unlock as you get home for totally hands-free unlocking (optional). With Auto-Lock and DoorSense, your home automatically secures once your door is closed, or after a set amount of time., WORKS SEAMLESSLY WITH YOUR SMART HOME: Built-in Wi-Fi allows your lock to work with your favorite voice assistant, including Amazon Alexa, Google Assistant, Apple HomeKit, Samsung SmartThings and more., ,