Compatible robots: Polaris 180, 280, 360, 380, 480 Pro, 3900 Sport, compatible with Polaris 91003105 / 9-100-3105 / PP-91003105. Size: Outer diameter: 4.3 cm; Inner diameter: 1.4 cm; Length: 7. 3 cm Easy to install: Simply replace the worn tail cleaner with a new tail brush at the tail of the pipe.< /p> EFFECTIVE CLEANING: These absorbent filter sponges contain uniform parallel holes to effectively capture large debris, particles and eliminate pool cleaners , they also help to scrub the bottom and sides of the pool. Great value for money: 12 x foam brushes, no need to change every week.