This 450mm solid top manhole cover is made from strong AP9 grade polypropylene.Like all manhole covers, the size refers to the clear opening size in this case 450mm.It has a 3.5 Tonne load rating, which makes is suitable for domestic driveways, pedestrian and landscaping use only.The actual overall size of the cover is 550mm x 50mm. This cover can be fitted to all 450mm diameter inspection chambers.The cover comes with a dual locking facility, both the cover to the frame and the frame to the inspection chamber. This cover has an enhanced slip-resistant surface tread pattern.This manhole cover is made by Clark-Drain.Plastic manholes, whether polypropylene or PVC, are all durable and long-lasting. Manufactured by injection moulding to exacting specifications , they will stand the test of time. They are considerably lighter than their cast ductile iron counterparts.All of our plastic manhole covers are made to fit directly onto the top riser ring of a plastic inspection chamber. Because o