Specification: black Material: foam filter Outer diameter: 4.3cm Inner diameter: 1.4 cm Length:7.3cm Compatiblewithrobots:Polaris180,280,360,380,480Pro,3900Sport Size:outer diameter:4.4cm;inner diameter:1.3cm length:7cm; Simple installation: it is enough to remove the wear brush, then replace it with a new pipeline The pool tail can replace the used rings during a pool cleaning day to ensure that algae, dirt and soil debris, walls and areas are removed from the pond area Polar star models of the northern zodiac: 180,280,360,380,480and3900. Adapted part number:Polaris91003105/9-100-3105/PP-91003105.