From the link you posted I derive you are talking about a Vivitar Series 1 70-210mm lens. Just for the records, there are numerous other Series 1 lenses from the past and even contemporary Samyang lenses get branded as Series 1.
However, there are at least 3 different main variants of the 70-210, in particular there are 6 versions. The older variants with better reputation were 70-210/3.5, the newer, presumably Cosina made are 70-210/2.8-4. If I were you, I would take a camera or a lens with me and compare the mount.
However, Vivitar used to designate the mounts with imprinted abbreviations mostly on the aperture ring:
- "PK" or "K" for plain vanilla K-mount,
- "P/K-A" for K-mount with A-contacts,
- "R-P/K" for the Ricoh-variant of the K-mount,
- "PK-A/R-PK" or "PK-A/R" or "P/K-A R-P/K" for K-mount with A-contacts and Ricoh pin,
A heads up for the Ricoh variants of the K-mount: Pls spend some time on an internet research for the keyword "Ricoh pin"
Another heads up: Some lens makers designated the Konica AR-mount as "KAR" - which frequently gets confused with Pentax KA.