Extension Collar for SP1070 SeriesSkim-Master is a non-corrosive, non-conductive, large capacity automatic surface skimmer featuring a round, tamper proof access cover, self adjusting 8 in. weir with a stainless steel spring, dual outlets and threaded internal connections for pressure testing. The optional float valve and bypass valve provide a suction outlet thru-skimmer system and an automatic bypass for low water conditions. The SP1070 Series Skimmers include a 3/4 in. knockout port that guards against pool overflow or can be used for pool water refill.