The EF-4 series filter removes solids down to 1/16" and greatly extends the life of the septic system. The EF-4 Combo includes the 4" standard length (14" rise) T-Baffle™, the EF-4 filter, and the B4035 bushing for reducing the outlet from Sch. 40 to SDR35 pipe. Made for easy installation and use, it will help ensure the best service life possible.