First Alert’s CO710 CO alarm is powered by sealed, ten year lithium batteries to provide continuous protection for ten years without battery replacement, and a built-in end-of-life alarm lets you know when its time is up. Its modern, compact design allows easy tabletop or wall mount placement, and it displays CO levels along with room temp on a backlit display. The unit’s “peak” function captures and allows you to retrieve the highest CO level recorded in your home. In the event of a CO incident, this valuable information can be passed along to emergency or hospital staff. The CO710 averages 4.5 out of 5 stars on Amazon, where its list price is discounted 47% to $31.66. See this deal on Amazon.