Garbaruk 1.8mm Spacer XD/XDR Conversion Garbaruk 1.8mm Spacer XD/XDR Conversion is a CNC machined aluminum 1.8mm spacer, which when placed on an XDR Freehub, allows you to use your SRAM XD cassettes on your XDR wheelsets. Not much else to say on this--SRAM designed the XDR Road / Gravel cassette and freehub standard to accept the MTB XD standard if a 1.8mm spacer is inserted on the XDR freehub before the XD cassette is installed. This slim, precision conversion device allows you to crossover your MTB cassettes onto your road / gravel XDR wheelsets, super useful if you have a particularly hilly gravel race or if you're trying to prevent the dreaded hike-a-bike of death during your next group gravel ride. Ask me how I know! Machined in Poland from 6061 Aluminum to ISO standards.