Easy installation: Easy installation could help you to save more time. , place the smaller, thicker o-ring onto the threads of the tank adapter.Secondly, place the larger, thinner o-ring onto the gauge housing. R0552000 tank adapter with union and O-ring 4-piece compatible with for Zodiac DEV series D. models DEV48, DEV 60 and series filter models 100, 150, 200, 250.Also compatible with for Zodiac DEL, CV, , CJ and series filter. R0552000 tank adapter with union and O-ring 4-piece is made of high-quality plastic and brass, waterproof, , -, good elasticity, good sealing, not easy to break. Precautions: If it is the first replacement, you need to pay attention,never pump while standing within five feet of the filter or operate the filter system at more than 50 psi of pressure., Weight: 0.220462262 Pounds, Manufacturer: Wesafrae