Universal Security Instruments Hardwire Smoke & Fire Alarm, with 10-Year Battery Backup

This product has some unique features: it is "off" and inactive until it is installed onto its base. Once "on", it will stay on until irreversibly deactivated with a provided plastic key. It can be installed in a no-tamper configuration. The claim is that it has a ten-year backup battery. I will have to get back to you about that. It is spec'd to be hard wired, line operated. Supplied with the usual Black, White, Red pigtail / connector. It is multi-sensor for optimum fire detection and interconnection with other units. It has verbal and tone alarms / prompts. Intended for professional installation and code compliance at an attractive price point, this is a quality product with special features. Even so, READ THE INSTRUCTIONS. Especially the "ON" function and deactivating for disposal A professional touch: it comes with an elastic shower cap to protect the device from sheetrock dust and worse during construction. it is better than I expected for the price