High mast lighting assemblies are specified by pole height and by photometric type. The standard pole heights are 100', 125', 150', and 175'. The photometric types are Types A, B, and S:

Type A and B high mast luminaires have asymmetric optics. This means that instead of creating a round light pattern, they create a long narrow light pattern that works well for lighting a roadway. All Type A or B high mast fixtures on a ring are required to be mounted level and oriented the same direction, typically toward the road. Since they are radially spaced in a ring, the optics must be rotatable to allow aiming.

ype S high mast luminaires have symmetric optics which create a round pattern around the pole. The luminaires must be mounted level, but since they have a round pattern they do not require rotation of the luminaire.