this is a friends and apears to be new it was used about 2 weeks product description-$100-Designed to operate within a sump or along side a sump style filter. Quadra-Helical injection of the dense foam produced by the Turbo-Eductor into the large reaction column maximizes reaction and skimming efficiency. The heavy-duty gate valve on the return line allows for fine adjustment of the water level within the reaction chamber while the protected water return pipe helps to minimize any bubbles from exiting the skimmer. Large waste collection cup holds over 1 quart. Heavy duty, ozone resistant, ABS plastic construction. Each unit is 8" wide and has 3/4" barbed inlet and a 1" FPT outlet. (30" tall, aquariums to 575 gallons, requires 1500-1800 gph water pump)