Some shoes have especially deep wells in the soles for housing the threads into which you screw your pedal cleat bolts. Shimano is aware of this, which is why they supply the world with long bolts for use in this case on the cleats for their Dura Ace PD-7810 and Ultegra SL PD-6620 pedals. Please note that all you're purchasing here are bolts-not cleats as well. If you need replacement cleats, you'll need to purchase those separately. These bolts are 13. 5mm in length, and one packet of long bolt hardware is enough for two cleats.