Genuine Meyer OEM B Check Valve Assembly 15959. Fits (early) E-58H, E-68, E-78, E-88 Units ONLY!!!! Packaging from Meyer varies. This was a common failure part on the Xpress E-88 (E-68 too). This replaces the original poor design in the E-88 (with the O Ring that split, no more O ring). How do you know if your E-58H is an "early" model? IF it came yellow with no cover, it defintiely is. IF the (3) Coils on the unit are identical in size and shape, and are METAL, you have an early E-58H unit. IF the Coils on your E-58H are made of plastic, you have the most current version, and this part will not work for you.