... . 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 window ... . 50mm CNG gauge, bottom connection, 1/4BSP, polished 304 SS case and crimped ring, polycarbonate plastic window, electronic borad inside the ...