Jacuzzi® - JPC, Air Switch (Used in HB21000) - ZP1521U1, TBS-310A
Note: Jacuzzi® has replaced the ZP1521U1 Air Switch with the TecMark TBS-310A (Pictured in Main Photo). The TBS-310A fits in just as the ZP1521U1 did. The new version does not utilize, nor require, the nut that holds the tubing.