Auxiliary Infantry 'A'

• Of the form of Coolus Type-I, but lacking the qualities of a legionary helmet. The bowl is straight sides with a flattish top at the centre. There is no thickened edge. 
• Where the line of the neck guard rim steps down in the region of the ears, one side is cut at an angle of 45o and the other is a right angle.

Auxiliary Infantry 'B'

• A very simple bronze skull, having straight, sloping sides with a flattened, rounded top. At the rear, the skull reaches the level of the wearer's ear lobes. 
• The reinforcing peak is placed high up and close to the extreme curve of the bowl.

Auxiliary Infantry 'C'

• Bronze. A hemispherical bowl, with a strong, upstanding cross reinforcing.
• The reinforcing peak is flat and crescentic, riveted at each side and with a central tongue passing through the helmet before being hammered over inside. 
• The back rim is slightly flanged outwards.

Auxiliary Infantry 'D'

• This type shows eastern influence. It is bronze, of globular form in the lower half, rising into a hollow conical apex surmounted by a conical button on a double-stepped base. Just behind the wearer's ears, there is a right-angled step down. To this extension, a neck guard would have been riveted (or a mail coif).