Shimano Ultegra 6800 Quick Release Skewer The Shimano Ultegra 6800 QR Skewer is based on the internal cam design created by Tullio Campagnolo many years ago. An internal cam is completely shielded from contamination, increasing the life of the skewer. It will also provide more clamping force, holding your wheel tighter than "lightweight" external cam skewers. | Shimano Ultegra 6800 Quick Release Grey, Rear