Making our DA7800 Hudz gave us a good blueprint for the Ultegra version. The key difference is that the ULT6600 compatible levers Ultegra, Ultegra SL, 105 R 700 for 10 speed all feature a wider profile and a longer lever body making it necessary to reduce the amount of height added while keeping overall volume similar. Our Original Enhancement Brake Hoods started it all. The goal was simple to mimic the firmness and texture of popular OE hoods while creating a more ergonomic shape. And since we were making these new hoods, we figured that offering them in a range of colors would be a good idea as well. SoftGrip the name pretty much says it all these are 25% softer and provide 80% more grip than our Original Enhancement Brake Hoods. They can serve as a way to help tame the pounding of rough roads or as the ultimate enhancement for a cyclocross bike. LeverSystem Compatibility: For use with 10 speed Shimano Ultegra 6600, Ultegra SL, 105 series 5600, and R700 systems including 6600, 6601 and 6603 STI levers. Not compatible with 8 or 9 speed STI levers of the same component ranges. OE Replacement Part Number: Y 6K2 98100.