The Vario has eight o-rings that need periodic maintenance. There are four o-rings around the pistons on the pump handle. There are two small o-rings around the top cap of the pleated cartridge, one large o-ring around the main body of the Vario, and one large o-ring on the underside of the ceramic disc. All of these o-rings need to be clean and lubricated to ensure a proper seal and proper function.