Shimano:Our original Neo hub has evolved to be stronger and more reliable than ever. The additional stress of larger cassette cogs, more capable bikes, and even more challenging trails led us to create the Durasync: 6-Pawl design with a 36 point/10 degree engagement and 3 chrome steel bearings.This freehub is a direct replacement for your Neo hub. The freehub includes pawls, springs, pawl retaining ring, red freehub spacer, and spacer for 9 and 10-speed cassettes. Chrome Steel Bearings are pre-installed. The freehub is splined to accept any traditional Shimano style cassettes. It is not compatible with SRAM XD style cassettes.SRAM:Our original Neo hub has evolved to be stronger and more reliable than ever. The additional stress of larger cassette cogs, more capable bikes, and even more challenging trails led us to create the Durasync: 6-Pawl design with a 36 point/10 degree engagement and 3 chrome steel bearings.This freehub is a direct replacement for your Neo hub. The freehub includes pawls, springs, pawl retaining ring, red freehub spacer, and spacer for 9 and 10-speed cassettes. Chrome Steel Bearings are pre-installed. Compatible with SRAM XD style cassettes. Not compatible with any Shimano style cassettes