This dual sided socket is designed to work with the new Shimano DA-9000/XTR-BB93 bottom bracket as well 6800 Ultegra and 5800 105 11spd groups (BBR-60). While most other manufactures cast or forge their bottom bracket tools we machine ours. Forging is indeed stronger but it lacks the precision that machining gives you. Whenever you're dealing with anodized surfaces great care needs to be taken to keep those surfaces from getting marred, gouged and striped out. That can be nearly impossible with some spanner style tools and difficult with other loose fitting sockets. Our sockets get precision machined from 7075 aluminum billets then hard anodized for a long lasting finish. What it all adds up to is a tool that's worthy of the bikes it's designed to work on and then some. The most unique feature about this tool is the inner nub, that nub in the center of the tool is the same size as the crank spindle. What this does is give you a second point of contact that keeps the tool from camming off of the part. when trying to remove stubborn cups.