The short and long pots differ by the length of the threaded portion of the shaft---Short's are 3/8"-inch and Long's are 3/4"-inch. Gibson Les Pauls that take long shaft pots: Standard's Faded's Classic's Studio's Traditional's 50's & 60's Tributes Historic '68 Custom RI 1977-current Custom's 1977-current Deluxe's 1977-1982 Pro's Gibson Les Pauls that take short shaft pots: Historic R4/R5/R6/R7/R8/R9/R0 1952-1977 Standard's 1954-1977 Custom's 1968-1977 Deluxe's Historic R7 Custom The Paul's Les Paul Special's Les Paul Jr.'s Of course, with Gibson, there are lots of transitional changes, custom one-offs that may not follow the list. ALL EPIPHONES TAKE SHORT SHAFT POTS! (the only exception is the Epiphone Les Paul Elitist) There is no difference in Tone between Short & Long shaft pots. Tip: Long shaft pots will fit in ANY Les Paul; adjust the nuts for proper height above the top.