Whether you want the BBT-4 or the BBT-7 ( http://www.parktool.com/products/det...=25&item=BBT-7 ) is going to be determined by whether you have a cartridge-type bottom bracket or a cup-and-cone buttom bracket. The BBT-4 has rounded teeth that fit the cartridges, whereas the BBT-7 has squared off teeth that fit the lockring on the cup-and-cone bottom bracket. If you have a cup and cone bb, you also will need a pin spanner and a box end spanner (both of which are combined on the Park Tool HCW-4).