Check the listing for details. Culligan OR-34 O-Ring of 4.125-Inch Diameter. Condition: New. Listed at 10.40 USD. 3/4" Housing O Ring. - 3/4" Housing O Ring, Use With Model #HF-150A Or Model #HF-360. - The OR-34 o-ring gasket is used to seal the housing bottom to the housing top to prevent leaks. - Or Model #HF-360.