Jet Helmets & Police Helmets Jet and police helmets are the classic styles. These open-face helmets allow you to enjoy the biking experience all the more intensively. If you are intending to buy a jet or police helmet, the most important thing is to check that it sits firmly but without uncomfortably tight. It is also important to decide whether you want to wear the helmet with a visor or separate protective goggles. Almost all jet and police helmets in the Louis range meet the safety requirements of the current test standard ECE 22.05. If you're in any doubt, you can order two different sizes from Louis online and try them out. Louis will take back any item that does not fit or which you do not like.