This 340mm solid top manhole cover is made from strong PVCu.The actual overall size of the cover is 340mm x 340mm x 85mm and it is for use with 300mm chamber risers.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 of this they are most commonly used in new build applications.Replacing broken manhole covers is always tricky. The abiding rules are that you must ensure that the correct load rated cover is selected, and that you measure the clear opening of the manhole rather than the old frame or cover and make sure that the new cover has at least the same size clear opening. Unfortunately we are unable to supply covers without frames. All replacement covers must be fitted in their own frame, which means removing the old frame.