Maytronics Dolphin Diagnostic Non Return FlapThe Maytronics 9985280, a Non Return Flap, is a diagnostic component designed for Dolphin robotic pool cleaners. This part is constructed of gray plastic and features a slightly curved, long rectangular shape with seven long round tabs and four rectangular extensions on the back. It is compatible with various Dolphin models, including the Advantage, Advantage RC, Advantage Plus, Advantage RC Plus, and Advantage Plus Pro RC.