double chain sprocket for hatch cover chain 1. six,seven teeth 1. double chain sprocket for hatch cover chain.It is used for the vessel sailing on the sea.2. We can produce the sprocket chain according to your drawing and dimension.3. We can also supply other sapre parts for hatch cover such as,Quick Acting Cleats, shackle of hatch cover, hydraulic pump unit, roller, balance wheel, etc.