Please look at photos. It comes with the unit and instructions. Missing mount.

This is a Google Nest Protect smoke and carbon monoxide alarm in white color. It is a battery-powered device with a rechargeable battery. The model number is 06A and it is compatible with Nest smart home system. It uses Wi-Fi to communicate with other Nest devices. This alarm is designed to detect smoke and carbon monoxide and alert you in case of any emergencies.