This item is a GERMAN SPRING BARREL CORKSCREW with a PAPER CLIP STOP. There is a paper clip type device above the spring that is inserted into the shank to stop the spring when the corkscrew is inserted in the bottle. After the cork is removed, one can remove the clip from the shaft, elevate the spring and remove the cork from the shaft. This corkscrew has a good sharp worm.
German Spring Barrel Corkscrew