This Maytronics Dolphin™ 3885000 White Wheel Bearing Stopper Ring for Dolphin™ Robotic Cleaners is a reliable replacement part, designed to seamlessly intergrate with the original pool cleaning system. The stopper ring creates a connection, and proper pool cleaner operation. Maytronics pool cleaners help keep your pool healthy and clean, which is of the utmost importance. Ensure that your pool cleaner is running as cleanly as possible with this certified genuine part.