Converts POL LP tank to Qcc1/Type1 hoses and regulators. The female one is QCC1 (type 1), the male has QCC1 (outside thread) and P.O.L (inside thread ) ; Propane Tank Gauge converts your old POL style connection type propane tank to new type (Type1/ Qcc1) Three zones "Green" "Yellow" and "Red" shows level of gas used. ; Monitors fuel level without removing the tank. The needle and the gauge levels both glow in the dark so it can be viewed in low light situations. No tools required, Easy and quick to install to propane appliance. This will work on Rv propane tanks, 3 point shut off handle tanks as well. This propane gas guage adapter is screwed to the left (inverted) to the gas cylinder. Make sure it is 'seated' properly before tightening, otherwise the threads won't line up and it will leak. It should tighten easily at first, then get tougher as it gets closer to being tight. Fit for-RV Camper Cylinder Converter, 10lb, 20lb, 30lb 40lb 100lbs propane tank We Highly Recommend That You Measure The Size Of Your Original Parts and Compare Them To What We Have Listed Before Your Order