The unique ITG Tri-Foam system has three progressive layers of foam impregnated with special ITG dust-retaining fluid. The foam combine with the arresting stickiness of the dust-retaining fluid to give a high level of filtration, without impairing air flow.

Performance is unaffected by large quantities of dirt arrested in the filter and loss of pressure in the airflow is very low. In normal use, a Profilter is claimed to last at least four times as long as the equivalent standard filter.