If your snow foam lance has stopped foaming properly then this could be your solution!
Simply slot out the metal pin from the black plastic nozzle cover and slide it off. Screw apart the bit inside and you will see the filter to be replaced.

This is replacement meal gauze for inside the foam lances and are required when the quality of the foam being produced by the lance starts to drop. This is because the gauze within the body of the lance can become clogged with soap scum and debris over time.
These gauzes are easy to replace (just some basic tools required).
We do recommend you flush your Foam lance through with clean water after each use.