Power Gunite Jet, Massage Internal, White 212-7740G, 212-7741G, 212-7747G Once the jet is plumbed and gunited into the spa, the internals are interchangeable and serviceable same as a portable spa. Four nozzles (1/4" to 5/8", 8gpm to 25gpm) are shipped with power gunite jet internals. 4-15/16" face diameter