This Worcester Bosch Greenstar Central Heating System Filter 22mm is an essential component for your boiler. It is designed to provide optimal filtration for your heating system, ensuring that dirt and debris are effectively removed. This will help to prevent damage to your boiler and ensure that it is running at its best. This filter is specifically designed for use with Worcester Bosch Greenstar boilers, and is easy to install. It is a standard size of 22mm, and is not a custom or modified item. Whether you are a homeowner or a professional, this filter is an important part of your boiler maintenance routine.