The "x18" is the measurement your after, 18mm from outer face of bearing/bb shell to end of axle.
Offer is still here by the way
Klein Attitude 91 BF XTR owned since 93, Kirsten BF, Adroit 93 Gator, Merlin 90 XT, Formula 1 92, Orange CW 92 OR/WH LX, Raleigh Metropolitan 87 Burgundy, Giant Super Sierra 89 XT, DB Axis smoke XT, Overburys Pioneer 89 DX, Dale 88 Suntour, Saracen Trekker 88 Deore x2, Tuff Trax 87, Dale Syn Hi-Mod 12 Ultegra
PROJECTS Funk 90 Centaur, Klein Rascal 93 Gator, Att. 90 Dolo, Adroit 91 Backfire, Adept 93, Kirsten 89, Palisades Trail 88, Trimble Inv4 88.
For sale XT NOS Shark Fins viewtopic.php?f=2&t=315332&hilit=Shimano+shark+fins