Rio Coral Feeder is specifically designed for the direct feeding of liquefied and particulate foods to SPS corals, LPS corals and filter feeding corals. Coral feeder can also be used to eradicate detris and excess debris from those hard to reach areas of the aquarium. Use with phytoplankton, oyster eggs, Cyclopes, liquid coral food, baby brine shrimp, rotifers and copepods. Just suck up your desired food in the coral feeder, place in aquarium and aim and shoot. Small:7"(18cm)feeding tube&10 1/4"(26cm) total length. Medium:9 3/4"(25cm)feeding tube&13 3/4"(35cm) total length Large:14 3/4(35.5cm)feeding tube&19"(48cm) total length Large extension tube 12 1/2"(32cm)