Selector Pin - for all gyms except the 1400 and 1600 made after 1/05. Works on both current 10 pound and current 15 pound weight plates (because they have the same depth and flat fronts for the magnet).
See PN53600 for older (arcing front) 10 pound plate based stacks.
See PN20760 for older stacks with 15 pound plates.
More part numbers for your reference:
PN17080 Screw for guide rod top
PN16520 Black nylon spacer for guide rod
PN11340 Threaded guide rod insert
PN26130 Rubber finish washer
PN20660 "U" clip cable retainer
PN29190 Screw to top plate and shaft
PN60700 Top Plate
PN53600 Older selector pin for no 15LB plate stacks
PN20760 Older selector pin for 15LB plate stacks
PN60610 Current selector pin, used since 1/2005
PN46700 Selector shaft 15 plates
PN20630 Selector shaft 20 plates
PN69600 Selector shaft 25 plates
PN57670 under stack Bumper (need 2)