Hydrogen Gas Detector for Battery Rooms - International Gas Detectors
Kidde Firex Plug-in Carbon Monoxide, Propane, Natural and Explosive Gas Detector, 9-Volt Battery Backup & Digital Display 21029623 - The Home Depot
Gas Leak Detector, TopTes PT199 Natural Gas Detector with Audible & Visual Alarm, Portable Gas Sniffer to Locate Combustible Gas Leak Sources Like Methane, Propane for Home(Includes Battery x2)-Orange - Amazon.com
501AK Handheld Battery Operated Combustible & Toxic Gas Detector
Airgas - B86E2829 - BW Technologies by Honeywell Battery For GasAlert Extreme Multi-Gas Detector