These were used on the LWB 1968-1973 models (and maybe a few other years). This one is in very nice condition and includes the mount, cancel ring and rubber buffer.
We just had an interesting discussion about these at the Early 911S Registry (a forum that I have been a member of for over 25 years). There were two versions of these made, the regular one and a lightweight one for the 1973 RS Carrera. The lightweight ones are rare and expensive but they break easily and are not really suitable for use.Â
You will find the interesting discussion by some very knowledgeable folks at this link: