This is a vintage lens, an Ernemann Detectiv Aplanat No.1, f6.8. It's mounted in a working Ernemann shutter. The high speeds on the shutter seem to work well, but the slow speeds (1, 1/2, 1/5) are all running slow. The settings for time and bulb both operate properly. Both the diaphragm and the cable release work fine. Most importantly, the glass is clean. This is just an educated guess, but the focal length seems to be close to 135mm. The wooden lens board is 2 3/4" wide. Shipping , US only.