Polypipe Underground Drain Inspection Chamber Base 460mm for 110mm Pipes is used to allow for easy inspection and maintenance of a drainage system. The base benefits from 2x45 degree and 2x90-degree side branch inlets for 220mm pipes with 3 blanking plugs if needed. It features a simple seal and snap cap system for strong and durable joints. Should be used in conjunction with UG510 cover and the UG431 Side Riser and UG488 Riser Sealing Ring if needed.