D Series: Laminated - GRP column / Elliptical man hole / Design pressure: 2.5 kg/cm²
DT Series:Laminated - GRP column / Elliptical man hole / Methacrylate sight glass / Design pressure: 2.5 kg/cm²
DC Series: Laminated - GRP column / Elliptical man hole / Lateral man hole / Design pressure: 2.5 kg/cm²
DS Series:Laminated - GRP column / Elliptical man hole / Methacrylate sight glass / Design pressure: 2.5 kg/cm²