This alarm can save lives easy to mount and operate temporary mute photo electric operation reliable alarm via loud warning sound approx 85 db 3 m and through red led test button for checking to see if it is still working properly led display shows ready to use 30 day battery low indication within this time guarantees full function during this time stainless steel protects smoke chamber from insects getting in technical details 3 v operating voltage volume approx 85 db3