Based on this product's specifications, here are some alternatives and similar models
Carbon monoxide alarm Stabo CO Alarm IV Wireless, battery powered 3V, white
Summary description:
Stabo CO Alarm IV Wireless is a battery-powered carbon monoxide detector for home use. It operates on a 3 V lithium battery and features wireless connectivity in a white housing. Supplied as a single unit with CE compliance, it alerts occupants to dangerous CO levels and is suitable for installation in living areas to improve household safety.