We offer most of our water tank lids in food grade PP (polypropylene) with a 5-40 cm screw thread and rubber gasket with vent, without vent or as a tank lid with a float valve. See the selection options on the left under "Category" or filter by the required tank lid size for your water tank. The tank lid size in cm refers to the clear opening on the water tank. Due to the permanently moulded threads for the lids on the water tank, only our tank lids listed here will normally fit the tank. For more information on individual tank lids, please see the relevant product page.