Garbaruk's entry into gravel drivetrains! Garbaruk mills the first 11 cogs from a single piece of heat treated hardened steel and adds a securely fitted 44 tooth aluminum sprocket to create the lightest gravel cassette for XD / XDR freehub. At 280 grams it's the best lightweight option for your Gravel bike. Compare to the XD-1251 at 412 grams and the XD-1271 at 373 grams. That's a big weight savings.This product is a SRAM XD specification, but it also ships with a Garbaruk 1.8mm spacer if you'd like to use this cassette on your XDR freehub. Officially compatible chains are: SRAM 12-speed Flattop chains, including T-Type chains. The cassette is not compatible with SRAM Eagle chains, Shimano, KMC or YBN. So this is a "gravel" spec cassette rather than an MTB spec cassette. Use standard SRAM cassette removal and installation tools--the same as you use on your SRAM XPLR cassettes.Tightly packed gears--perfect for gravel riding: 10-11-12-14-16-18-21-24-28-32-37-44 and monoblock design (made out of hardened steel) with only largest cog made out of aluminum. Gear Range: 10-11-12-14-16-18-21-24-28-32-37-44Fits XD and XDR Freehubs (with included spacer) Only100% Silver colorway - we're 100% silver here at JefeCompatible with SRAM 12-speed Flattop chains, including T-Type chains. The cassette is not compatible with SRAM Eagle chains, Shimano, KMC or YBN. Garbaruk 12-speed 10-44T cassette is designed for XD-freehub gravel bikes and XDR freehub gravel bikes (with included 1.8mm spacer). It is designed to work with all SRAM XPLR line derailleurs. Manufactured in Poland with precision CNC instruments and ISO certifications.