Speedy Plastics Supply All Types Of Underground Drainage Manhole Inspection Chamber Bases For Shallow And Deeper Applications , We Stock The 110mm 5 Inlet 450mm Fixed Manhole Base, 110mmm 3 Inlet 320mm Fixed Manhole Bases And The 110mm 5 Inlet Version As Well . Underground Drainage Manhole Inspection Chambers are available here at Speedy Plastics in all Diameters & Depths From Shallow Chambers To Deep Inspection Chambers, Deliveries 1-2 Days