The Coleman Digital Fuel Gauge indicates the amount of fuel remaining in portable propane tanks used with tabletop grills, portable heaters, lanterns, mosquito foggers and other propane-powered appliances. This pocket-sized device is easy to use whether you are out and about or in your garage. Designed with user-friendly functionality, the fuel gauge features an easy-to-read, digital LED display to indicate the amount of fuel remaining in your cylinder. It operates on two CR2032 batteries, included. This digital fuel gauge is compatible with any non-refillable fuel cylinder with CGA600 connection, including 14 oz Propane fuel, 16 oz Propane Camping Gas and 14 oz MAP-PRO® fuel cylinders. To use the Coleman Digital Fuel Gauge: Power on gauge and select 14 or 16oz to match your cylinder size. Snap gauge onto cylinder neck. Lift scale with cylinder attached. Display screen shows estimated fuel remaining. Remove scale before attaching fuel cylinder to appliance. Ideal gadget to have on hand for tailgating, camping, backpacking, grilling.