The Hurlcon heater bypass plunger disk is available for the HX70, WX75, HX120, WX120, HX150, JX130, JX160 range of heaters. These by pass plunger disk does not come with the bypass plunger assembly, this is ordered separately. These heater bypass plunger disk are specifically for the Hurlcon heater and connects to the in/out let manifold. Order your new Hurlcon heater bypass plunger disk today.