This double-sealed aluminium recessed manhole cover from EcoGrid is manufactured from extruded aluminium with a 3mm galvanized steel bottom plate and a reinforcement mesh in the cover. Tested to EN124 to lorry load bearing, this recessed manhole cover has two seals. The first is at the base and the second is a T rubber seal on the outside frame that’s tasked with minimizing tension between the frame and the recessed cover, eliminating any odours from escaping, and for preventing a dirt build up. The manhole cover is waterproof and odour-proof. Please note: Manhole cover measurements are taken from the clear opening, the internal dimensions of the hole are taken to give the size manhole cover that is needed. This double-sealed recessed manhole cover is CLEAR OPENING SIZE and comes with specialist lifting keys provided by EcoGrid so that fitting and maintenance is easier. Double-sealed aluminium recessed manhole covers are available from 300mm x 300mm to 1000mm x 1000mm in 48mm and 68mm in-tray depths. For external use, this recessed manhole cover can improve the aesthetics of an area by allowing the manhole to blend as seamlessly as possible with the surrounding area. Instead of a large silver cover blemishing the landscape, the recessed frame is filled with the same substrate as its surroundings and the cover is hidden. This EcoGrid manhole cover can be used on tiled, paved and grassy surfaces. EcoGrid Manhole Cover Specifications Clear Opening Dimensions: 450mm x 450mmExternal Size: 510mm x 510mmIn-tray Depth: 68mmOverall Depth: 80mm Please note,the double sealed manhole covers are not lockable. If you require a lockable manhole cover please see our triple sealed options.