If you have a 2013 or later Zipp 188 rear hub, and you're looking to switch the cassette body from Campagnolo to Shimano/SRAM, or vice versa, this is the kit for you. Wondering what model year Zipp 188 hub you have? Look at the end cap on the non-drive side. If it's black, then you've got 2013 or later. If it's blue or red, you've got a 2009-2012 188 hub. If you're looking to convert that to eleven-speed, you need the Zipp 10- to 11-speed conversion kit. Though, if you're already running Campagnolo splines, those should take Campagnolo-splined eleven-speed cassettes without issue. If you're going from Campagnolo to Shimano/SRAM, you get a red cassette body, end cap, bearing shield, washer, and spacer for 10-speed cassettes. If you're going from Shimano/SRAM to Campagnolo, you get a blue cassette body, end cap, and one .25mm axel washer. In both cases, instructions are included. The Zipp 11-speed 188 Freehub kit comes with all the pieces you need to convert your eleven-speed 2013 188 Zipp hub from one empire to another.