Zodiac Jandy 1 1 2" S x 2" Spg 90° Check Valve (7511) leviton The Hayward indoor vent adapter The Hayward indoor vent adapter is designed for compatible Universal H250FD heater applications where a positive pressure indoor venting setup needs the proper transition fitting The Waterco Ful Flo spacer is designed for compatible filter applications where the correct spacing component is needed to restore the intended fit of the assembly Choosing the correct valve can help simplify the plumbing arrangement and avoid extra fittings that add unnecessary complexity This replacement is especially useful where the system needs both backflow prevention and a 90 degree turn in a single valve body