Two Little Fishes NPX Adaptor for Reactor 550The Two Little Fishies Phosban Reactor 550 NPX Adaptor is a vortex generator for fluidizing the NPX BioPlastic and other biopellets in theTwo Little Fishies Reactor 550. This will keep the biopellets from clumping to together and allow for the use of a smaller pump. The recommended pumps for use with the 550 NPX Adaptor are theSicce Syncra Silent 2.0 Multifunction Pumpand theSicce Syncra Silent 3.0 Multifunction Pump.Two Little Fishes NPX Adaptor for Reactor 550