Only about 900 of these lenses were built, many in Leica screwmount, and one in Exakta mount. The first batch, serial numbers 611xx are of more crude construction. The rest of the lenses, spread over a couple of different serial number batches, are basically the same.
The lens uses 40.5mm filters, and the shade is a heavy chrome slip on design. The rear cap would be heavy chrome as well, the front cap fits on the end of the shade, is also heavy chrome.