Liquid filled design for superior resistance to shock vibration and the elements.. Liquid dampened movement provides smooth pointer movement and extended service life in harsh environment applications.. Specially designed user-operated vent equalizes gauge case pressure allowing for calibration adjustments in changing temperatures and barometric pressures.. Includes bulb and socket assembly with red and green bulb covers. Includes 4ft. Braided stainless steel hose also requires #4 braided hose to connect isolator to fuel source. Use of isolator allows gauge to be mounted inside vehicle. Includes gauge mounting hardware and installation instructions