... electronic board on the window, brass internals and connection, dual scales 0-400bar/psi, accuracy 2.5%2. 50mm CNG gauge ... electronic board on the window, brass internals and connection, dual scales 0-400bar/psi, accuracy 2.5%3. 50mm CNG gauge ... , electronic borad inside the gauge, brass internals and connection, dual scales 0-400bar/psi, accuracy 2.5%