Allen inspection hatch covers are available in black, grey or white. Allen Hatch Covers are made from a lightweight polypropylene.
Hatch cover (non 'O' ring)
Allen has three different hatch cover designs:
A.137 and A.237 are a non ‘O’ ring design and have exposed fixings.
A.337, A.537 and A.637 all require a rubber ‘O’ Ring to keep them watertight.
A1737, A1837 and A1937 feature a fully threaded cover with watertight seal.
Fixing Hole size: 3mm
Cut out size: 109mm
Opening size: 99mm