Focorect coupled rangefinder made by H. Schneider & Co., Hamburg (which I don't think has anything to do with Schneider Kreuznach) for folding or other fixed lens zone-focusing cameras with a 32mm slip-on filter mount, such as the Voigtländer Perkeo II and others. I originally purchased this from Jürgen Kreckel, and it is in good calibration. Lens coating is somewhat mottled, but at least it's coated. Attach this device to your lens set to infinity, look through the rangefinder window, and you will be able to focus the camera as close as 1 m by means of the focusing ring on the device, which has its own optics. Because it has its own lens, you're sacrificing some optical quality for the ability to focus accurately and quickly, so it might not be as sharp as an image focused with a tape measure or with an accurately calibrated non-coupled shoe-mount rangefinder, but on the other hand, you'll be able to focus accurately in situations where you might otherwise just miss the shot or have to guess at focus. The rangefinder window is separate from the camera's viewfinder, so you still have to look through the viewfinder to frame the image, but you don't have to guess at the focus, and you don't have to read the focus distance from the rangefinder dial and then set the same distance on the lens. DOF calculator on the back. Includes the case pictured in the photo. $35 includes domestic U.S. shipping, a little more for foreign shipping.