This is the complete Waterway 3.5″ Hi Flo Suction Fitting. It uses a straight design and is designed for wall use. Hole Size: 2-3/8″ Cover Diameter: 3-3/4″ Plumbing Connection Type: 1.5″ Slip Wall Flow Rate: 128 GPM. Waterway Plastics is proud to design, engineer and produce their quality line of products right here in the USA, using only premium NSF Approved materials & meeting all Certifications and Standards.