I use a ST3614 on my fr651V. not a commercial mower. Wix makes a replacement (wix 57035, same size as the factory) but it's pricey. Ultra or Napa Gold have the silicone valve if that matters. Kawa filer was 49065-7007 if that helps. it does have the silicone valve. the auto filter are a little longer so check for room.