This access pipe is from Alumasc's Flushjoint downpipe collection, particularly from the array of square fittings and guttering they offer. It works in the same manner as a regular downpipe, except it has an opening where you can clear any blockages with relative ease.

Brand Name	Alumasc
Colour	Anthracite Grey
Material	Aluminium
Profile	Square
Downpipe Diameter	100mm x 100mm
Range	Flushjoint
Features & Benefits	Size variation, Up to 40 year life expectation, Recyclable extruded aluminium (grade 6063 T6) that is unlikely to rust, crack, and corrode, Suited to British standards (BS EN 12020:2001, BS EN 573:1995, BS EN 515:1993, BS EN 755), Versatile and easy to install, UK made.