This propane gas gauge lets you know when the propane in your refillable cylinder is running low. Gauge also detects leaks that could be potentially dangerous. Brass constructed gauge includes an easy in-line connection. Meets all Type 1 safety standards. Fits propane tanks from 5 lbs. up to 40 lbs. Durable brass construction Meets all Type 1 safety standards | Mr. Heater Propane Gas Gauge & Leak Detector