Detailed Product Description CNG pressure gauge ,install on to Gas Pipe,through check gas pressure, then send to switch to display the gas ... steel 1. 50mm CNG gauge, bottom connection, 1/4BSP, black steel case, snap-on polycarbonate window with electronic board on the window ... 5%2. 50mm CNG gauge, back connection, 1/4BSP, black steel case, snap-on polycarbonate window with electronic board on the ...