Tank tube 40cm

Measuring tips. We tried to measure the outside of each tank, the inside of each tank and the inside of each lid. The numbers varried substantially and that is one of the main confusions when customers order replacement seals. Procedure: Take a seal, fold it in 1/2, measure it and then multiply it by 2 this will give you an estimated circumpherance. Seals are labelled according the the diameters that they will fit. They are visually smaller than the lid but they will still fit. Procedure: Warm your seals in warm water so that they become more pliable and easier to stretch over the lid. They appear to go over 2/3 of the lid but trust us. Stretch the seal and they will fit properly.