Hayward SPX1600PN Swivel Nut and Knob Replacement for Hayward Superpump and MaxFlo Pump Swivel nut and knob replacement Fits hayward superpump models sp1600x5, sp1605x7, sp1607x10, sp1608x10, sp1610x15, sp1611x15, sp1615x20, sp1616x20, sp1621x25 Also fits maxflo pump model sp2810x15 Weighs 11-Pound