The Master Lock 4400D Bluetooth Smart Padlock is a modern and stylish option for securing your indoor door or locker. Made from high-quality boron alloy and metal, this rectangular padlock features a brushed black finish and silver accents. With the convenience of Bluetooth technology, you can easily share guest access, monitor activity, and receive tamper alerts. The smart padlock also includes features such as low battery warning and operates on one CR2450 battery, making it a reliable and secure choice for your home or property.