Catching a gas leak before it becomes a bigger problem is one of the smartest things you can do to protect your home and the people in it. In the Good Housekeeping Institute Home Improvement & Outdoor Lab, our engineers evaluate gas leak detectors for accuracy, reliability, ease of use, and smart features. This one covers carbon monoxide, an invisible and odorless gas, along with the natural gas and propane most homes actually store or burn. "I especially like the extension cord, which lets you plug the device into a low outlet but also mount it higher, where natural gas and carbon monoxide gas leaks rise," says DiClerico. Other gas leak detectors worth a lookBest Value General Tools & Instruments Combustible Gas Leak Detector Pen Best Value General Tools & Instruments Combustible Gas Leak Detector Pen Amazon Also Consider $64 Walmart $40 Lowe's This is the easiest gas leak detector to use, full stop.