Klein Tools has been making professional-grade hand tools for over 160 years. The ET120 Gas Leak Detector brings that same industrial reliability to finding gas leaks in your home. It detects methane, propane, and other combustible gases at concentrations as low as 50 parts per million. That sensitivity matters when you’re trying to find a slow leak behind a stove or near a gas line before it becomes a real problem.

The 18-inch probe lets you reach into tight spaces without crouching or contorting. Two sensitivity settings give you control: High mode catches traces between 50 and 1,000 ppm, while Low mode handles heavier concentrations up to 10,000 ppm. The audible alarm escalates as you get closer to the source, and the visual indicators confirm what you’re hearing. It runs on standard batteries, so you’re not hunting for a charger in an emergency.

The biggest trade-off is that it’s a single-purpose tool. You won’t use it every day, but when you smell gas or need to confirm a repair, it earns its place in the drawer. The alarm is loud enough to hear over a furnace or water heater, and the response is immediate. For homeowners who want professional-grade detection without calling a technician for every sniff, this is the straightforward solution.