The Two Little Fishies Xaqua InOut Overflow and Return is a complete overflow system featuring anti-clogging and an easily removable suction grid directional water jet. NOTE: Specialized equipment is required to drill holes in glass aquariums. The Xaqua InOut can be installed on aquariums with an external sump filter and two drain holes. The Xaqua In-Out is attached to the side of the tank. The special inner conformation makes it particularly noiseless and generates a wave effect on the water surface. For maintenance operations, such as cleaning of the tubes or of the o-rings, it is sufficient to lower the water level by 4 cm. With Xaqua In-Out you drill holes in the side of the aquarium and not the bottom of the aquarium. It’s made of molded plastic material with high resistance, non-toxic and shockproof. Maximum pump capacity 2500 L/h. Divisible into two parts to position the IN and the OUT in two different parts of the tank. External dimensions: 12 x 5 x 6 cm. Includes: - 1 INOUT complete with grid, support, 2 nuts and nozzle water exit. Includes - 1 O’ring IN (Code 4137) and 1 O’ring OUT (Code 150). INSTALLATION: To ensure a tight seal this device is equipped with O-RING positioned on the outside of their sockets. With INOUT in position the two O-rings have to be in contact with the outer side of the aquarium glass. Tighten the nuts by hand without the aid of mechanical tools. It’s important that the holes in the glass are perfectly calibrated to ensure the hermetic water seal. The drill template indicates the distances of the holes and the maximum and minimum diameter. Keep in mind that the larger the diameter of the hole and the more attention you should have to respect the distances indicated. Place the INOUT O-rings so that they are centered in the hole. Clean the hoses before use. Periodically clean the pump and the hoses to maintain the INOUT efficient.