Genuine Maytronics certified part. Has your pool robot started to struggle to climb up the pool walls? You may need to replace the wonder brush climbing rings. These foam rollers can be fitted to the front and back of any Dolphin combined brushes. They assist your Dolphin robotic pool cleaner in climbing the pool walls by providing traction, especially on smooth pool surfaces such as fibreglass or tiles where traction may be harder. 1 wonder brush ring per pack (4 required).