An absolute must for backwashing Pondmaster ClearGuard 8000 and 16000 Pressurized Filters because (1) it easily connects to the bottom of Pondmaster ClearGuard Pressurized Filters, (2) loosens stubborn pond waste in the pond filter by agitating the biological media and it contains Pondmaster air pump, water valve, tubing, clamps, and appropriate fittings.