This Model Is Most Current Version Of 5" Quantum Directional Which Threads Into Jet Body.Jet Body Options Sold Separately: Hole Size: 3-11/16" Mfg #Rd203-5001 - 3/4" Sb X 3/8" Sb Screw-In Mfg #Rd203-5002 - 1/2" S X 3/8" Sb Screw-In Mfg #Rd203-5003 - 3/8" S X 3/8" Sb Screw-In Mfg #Rd203-5004 - 3/4" S X 3/8" Sb Screw-In Mfg #Rd203-5005 - 3/4" Rb X 3/8" Sb Screw-In Specifications Category: Jets / Jet Parts Subcategory: Jet Internals RD203-5717