Here is the link. The main advantage is that it allows larger bearings and 8mm axles. Another thing about them is that there the only aluminum knuckles that allow the use of the dust boots (they were, there might be some others that do now). See the Revo bearings tend to blow out and the axles tend to bend with the 23mm hubs. The store is down now, but the knuckles are $100 and the 8mm axle kit with 23mm hubs is $100 as well. So $200 for both. You can use the knuckles without the 8mm kit, but not the 8mm kit without the knuckles.