10mm threads.
If you have lost your everlasting Gotz stopper, fear not! We have a direct replacement. Durable (unless you lose it), original equipment. Please be certain you have a Gotz brand endpin with the factory-supplied shaft which accepts the standard Gotz thread-on stopper before purchasing - many endpins have been modified by successive owners. Returns are only accepted in the event we ship the wrong item and what you receive is not a Gotz thread-on endpin stopper. See photos: 1) The Everlasting Gotz Stopper in repose; 2) Everlasting Gotz Stopper IN ACTION!!
If you need additional parts for your Gotz endpin, we Gotz ya (see what we did there?).
Gotz type stopper with 8mm threads