In use the film speed is set against a filter factor, the subject is sighted through the finder, a spring-loaded catch is held down to enable this, on releasing the catch the finder shows a black cross set against a white field, a wheel on the meter is turned until the cross is no longer visible. The shutter and aperture pairs can then read.

Different arrangements of the scale exist. The British patent is in the name of Drem Products Corporation of New York.

In use the film speed is set against the subject index, the subject is sighted through the finder and a wheel on the meter is turned until the subject is no longer visible. The shutter and aperture pairs can then read.

There are differences in the dial layout between models.