UG437 Polypipe Chamber Base Shallow Access 320mm Dia Black UG440 Polypipe Chamber Base 220mm Deep x 460mm Dia Black ICDB1 Polypipe 150mm Deep Inspection Chamber Base & 4 Risers Black ICDB2 Polypipe 160mm Deep Inspection Chamber Base & 4 Risers Polypipe Four Riser (for Deep Inspection Chamber Base) 860mm effective height Black ICDR4 ICDB3 Polypipe 110mm Deep Inspection Chamber Base & 4 Risers PolySewer Chamber Base 460mm Terracotta PS670 (Inc Seal) ICDR1 Polypipe 215mm Deep Inspection Chamber Base Single Riser Black UG670 Polypipe 160mm Chamber Base 460mm Dia Terracotta ICDR2 Polypipe 110mm Deep Inspection Chamber Base & 4 Risers