2 1/8" X 2 5/8" (54mm X 67mm)

No markings

Picture courtesy Bob Berry

2 1/8" X 2 1/2" (54mm X 64mm)

No markings       

{Found in Belarus}

Picture courtesy Tom Katonak

2 1/8" X 2 3/4" (54mm X 70mm)

No markings       

{attributed to Ukrane}

Picture courtesy Tom Katonak