When shopping with EPOOLS if you buy more the one product the freight may stay the same or increase slightly it would not double in cost so save and buy extra goods.
You pool water is dropping losing water? it may be the hydrostatic valve (Poolstore has three valves all with the same thread), You should replace the valve as over time all the pool chemicals have damaged the rubber gasket and o-ring
You may need a tool to remove the hydrostatic valve this tool will remove two of the three style valves
This Super Size cover is 227mm in diameter.
The underside has three screw anchoring stems at 140mm spacing.
Whats in the box:
Poolstore Hydrostatic Valve Super Size Cover with Screws and Plugs.