The Altecnic Robokit Extra Sealed System Kit includes a 24 Litre Expansion Vessel, an essential component for sealed central heating systems. This reliable and cost efficient vessel offers peace of mind upon installation, with multiple component siting options for system flexibility. Note: Sealed central heating systems are different from unvented mains pressure hot water systems, which only apply to the secondary hot water supply of a combined heating and hot water system. Nitrogen-filled heating expansion vessel Includes wall-mounted sealed system RoboKit Flexible installation options Cost-saving design Noise reduction Low maintenance costs Includes expansion Vessel, Filling loop, Safety relief Valve complete with gauge, Mounting bracket, Quattro 4 way connector * See technical attachments for more details.