Impulse/aspiration. Adjustable flow. Made of ABS plastic material and stainless steel screws. RECOMMENDED maximum flow rate according to standard EN 13451-1: 12 m3/h. Outer thread 2 , Ø interior 50 mmAvailable normal model and oscillating model.Available for concrete pools and for prefabricated pools.Multiflow systemThis system consists of the fact that the ball of the mouth is provided pre-marked with a series of diameters (14, 20 and 25) so that with the help of a punch (also supplied) and a mass can select one of them at the moment of the installation, thus obtaining several caudals. RECOMMENDED maximum flow for a maximum passage speed of 4m/sec., According to standard EN 13451-1: Ø 14 mm = 2.2 m3/h, Ø 20 mm = 4.5 m3/h, Ø 25 mm = 7 m3/h.