Astralpool Return inlet Multiflow. The multi-flow system: The eyeball has been marked with a series of “knock-outs” at 14, 20, and 25 mm, enabling the required flow to be selected at the time of installation. Recommended max flow 4 m/sec., complies with UNE 13451-1: Ø 14= 2,2 m3/h, Ø20 = 4,5 m3/h, Ø25 = 7 m3/h. To glue onto Ø 63 mm, outside 6 bar pipe and inside Ø 50 mm. Made in white ABS. It can be installed with wall conduits: 15661-15660. Grille slots are < 8 mm. Complies with UNE 13451-1.