Equipment/Numatic vacuum cleaner

We have a green Numatic "Henry" vacuum cleaner. It can operate in bagged or bagless mode. There is a filter which fits inside the case for bagless mode. The filter should not be in place if there is a bag in the cleaner. Using bagless mode with the filter dirties the filter, which is more difficult to clean than changing the bag. Bagless mode should be used if you are vacuuming up small particles rather than dust.