The Kent Marine Sea Squirt Invertebrate Feeder is 21" and extendable to 35" for deep aquariums or hard to reach areas. Graduations on the tube that indicate the volume of a supplement that has been drawn in.Features an extendable prong at the tip to deliver meaty foods to aquarium inhabitants. This is constructed of durable material that may be completely disassembled for thorough cleaning. Holds up to 10ml of liquid.