Balboa Gecko Spa Heater Gasket / O-Ring / Seal - (Heavy-Duty) Also suits Aquatemp, Hydroquip
Fits all Balboa Heaters and many others including Gecko, AEware, Hydroquip, Aquatemp, RMF, and others. May be black or white material. Should be replaced every few years.
Two (2) are needed and are sold as a pair.
Outside diameter - 74mm
Inside diameter - 53mm
Total Thickness - 6mm
Square edged O-ring side - diameter of raised ring centre to centre - 63mm