The Erac comprises a miniature camera, sold as the Merlin, enclosed in a plastic housing shaped roughly like a pistol. The Erac is described and illustrated in a patent (494527) issued to Harry Steward of Southend-on-Sea. The example shown here carries the patent number 379501 (other patents pending), that patent was issued in 1931 to Steward and Harry Covill, the camera described is also a pistol shaped device but is otherwise not related to the Erac.

The trigger release operates the shutter and advances the film via a large cogwheel.

The camera was sold under the name of Erac Automatic Pistol Camera or as the Erac Mercury I. The company was, at first, known as the Erac Selling Co. and later as the Erac (1946) Camera Co. located in Southend-on-Sea. The company was wound up in 1949.

There are slight differences between the two examples shown here - the first example has 'Made in England' below the name, the lens cone is dull metal and the front of the actual camera (inside the plastic housing) is black, the second example does not have 'Made in England', the lens cone is bright metal as is the front of the actual camera, there are also differences in the inside moulding and the screw holding the two parts of the case together.