Like HowStuffWorks on Facebook!

How NFL Equipment Works

Fitting a Helmet
Two tools that help with the fitting process are calipers and the inflation bulb.

The calipers (left) are used for measuring a player's head, and the inflation bulb is used to inflate air bladders inside a player's helmet, ensuring a more secure fit.

Miles starts the fitting process by measuring the player's head with the calipers. Based on those measurements, Miles chooses a helmet shell of the appropriate size and style. Next, padding is added to ensure that the helmet fits that player's head.

A player's helmet, complete with foam padding

Padding consists of both foam-rubber pads and inflatable (air) pads. Both the top and side padding include inflatable bladders that customize the fit. Once the helmet is in place on the player's head, Miles applies the inflator bulb to two points on the outside of the helmet.

It is critical to a player's safety that his helmet is fitted specifically to his head. The holes above are for the inflation bulb and are used to inflate the air bladders located in different parts of the helmet.

Next, Miles fits jaw pads to ensure that the lower part of the helmet is snug against the player's face. The helmets that most NFL teams use are remarkably light, and once the pads are in place, the helmet is essentially "glued on" -- there is no movement or shifting; it's as though the helmet has become a part of your head.