Our own silicone piston V seals for the Robot - Manual Espresso Maker, same seal for the current lever groups on the market. Each Robot piston requires 1 V seal. Please note that although the gaskets are strong under compression, you should never use a sharp tool like a screwdriver to install them. This may tear the silicone. As with any silicone seal, you should only use food safe silicone grease to lubricate them, do not slather it on, a sheen is sufficient. Dow 111 is a good choice. Item: Robot Piston Seal Product size: Approx. 49.5mm (OD) 40.5mm (ID) 6.75mm (Thickness) Product weight: Approx. 9g Colour: Red Material: Silicone rubber SGS food test report: Please click here Included in the package of Robot - Manual Espresso Maker? Regular Robot Yes, one installed on the piston and one spare Barista Robot Yes, one installed on the piston and one spare The original stainless steel tamper will be replaced by the Robot Levelling Tamper if you upgrade it with £35. Care and use: Install the gasket as the flat side is up and the V side is down. Water leaks if the installation is incorrect.