Kidde 21007426 KN-COPF-i Silhouette Wire-in Low Profile Carbon Monoxide Alarm, 5 1/4L&rdquo; x 5 1/4" H x 1 1/2&rdquo;D x (3/4&rdquo; Installed), White Innovative low profile alarm fits in most standard 2-gang, metal or plastic electrical boxes Pre-stripped wiring harness includes easy-off cap and does not require a stripping tool Rechargeable battery is turned on automatically when AC power is supplied Sealed Lithium-Ion rechargeable battery backup 7 year product life, 40-Percent longer than other CO alarms Green LED indicates power is being delivered to the alarm, red LED light indicates unit is in alarm and amber LED light indicates unit is the initiating alarm