If you have one of the old folding Ansco No. 2A or 3 cameras or the Folding Buster brown or V.P. Cameras then this is for you. Or get one for you collection of vintage camera accessories. The Portrait Attachment slips over the camera lens and in no way affects the operation of the camera, except that it enables the operator to work closer to the subject, thereby obtaining a larger and sharply defined image on the film. Barrel is 20mm diameter at the rear and 24mm diameter at the front. Clear lens diameter is 16mm. Unused in original box with instructions.