2.25" tall brass case which was made with no pin for wearing. Bottom edge has red notched plastic wheel which turns to show letter and numeral combinations in a pair of small cut-out center windows. Above the window is a slot for a tiny brass key which was used to set various combinations. The keys are much scarcer than the decoders and none is included with this example but offered as next item. Front is glossy brass and back has most original luster. VF.