Works with Alexa for voice control (hub required, Alexa device and hub sold separately). Requires 110-240V. Secure, keyless entry for your smart home. Lock and unlock your door, control keyless access and keep track of who comes and goes, all from your phone. Keep your existing lock and keys. Easily attaches to your existing deadbolt, so everyone can still use their keys. Stop hiding keys under rocks. Send guest keys from anywhere instantly—all from the August app. Control access for anyone. Grant access for a few weeks, a few hours, a few minutes. It’s up to you. Be sure you are secure with DoorSense. Only August has DoorSenseTM to tell you the door is completely closed and locked. Requires ios (9.0 or higher) or Android (5.0 or higher) smartphones. Locks automatically as you leave and unlocks when you arrive. Simple, DIY installation. Install in about 10 minutes with just a screwdriver.