Purchased this freehub body (driver), so I could replace the stock SLX/XT 11x1 drivetrain on my squish bike, with a GX Eagle set-up. All based on my outstanding long-term experience with GX, generally. The SRAM 12 spd cassettes require the use of a proprietary XD driver, to accommodate the 10T small cog. So I was very pleased to see that SR offers XD drivers for the SRC rear hubs I'm using. they offer both alloy and steel options. I tend to favor durability over weight - so went for the steel one. Quality is outstanding both in appearance and operation, so I expect this driver to last a good long time. The SRC hubs are very easy to service - even first time - so replacing the Shimano HG driver with the XD driver was literally a half-hour affair (much of which was getting the wheel off the bike, cleaning it up, yada yada). Didn't even worry about releasing air pressure in the tires. The driver installed beautifully. The kit included the end-cap I needed for my bike's boost spacing. With a little additional grease of my preference - installation was virtually plug-&-play. And the chainline is right on the money. Weird though - I'd swear that the the new driver is quieter, and hooks up more quickly. Thinking that the "quieter" part may be due to steel vs alloy, and new grease. It's been a month or two now - about half of that riding in good ol' PNW wet & muddy conditions, and no change. Good news, eh? As for the seemingly quicker hook-up - I have no idea. The pawl configuration on the XD driver is same as the HG one - and I sure didn't change-out the ratchet ring in the hub - so that can't be it. I suspect the drivetrain itself, and a shorter lag-time that the chain needs between cogs. ANYWAY - off the point a bit. Simply put - I'm a happy camper - both with product quality and with customer service. I've owned a variety of Hayes brakes over the years and found the same. I've run Manitou forks several times (currently a Magnum Pro on my winter bike) and again - have found quality & service to be outstanding. Good stuff, Maynard!