These are quite cool, even though they're RD. (Being IBM, they're the best RDs you can find.)
They're quite close in appearance to the Model F p/n 1387033 (buckling spring), but not exactly. Hence they're unique in the IBM keeb canon.
The price on this one seems somewhat steep. A couple have [urlhttps://www.ebay.com/sch/i.html?_from=R40&_nkw=ibm+73X3860+&_sacat=0&LH_Sold=1]recently gone for considerably less[/url]. If I were interested in this, I'd point that out to this seller and ask them to consider adding the "Make an Offer" option.