This Maytronics Dolphin™ 3862258 O-Ring for Wave 300 Top Cover Locker for Dolphin™ Wave 300 is a reliable replacement part, designed to seamlessly intergrate with the original pool cleaning system. The O-Ring ensures a tight and secure connection within the cleaner. 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.