StopTech GCX Rotors with Elemental Protection GEOMET coating on all non-friction surfaces provide long-lasting corrosion resistance while promoting efficient rotor cooling. GCX rotors offer class-leading application coverage as well as superior protection from corrosion and rust. GCX rotors have been engineered to restore OE performance while offering maximum durability and extended service life. GCX rotors feature partial Elemental Protection GEOMET coating on the friction surface that results in 10 percent faster pad bed-in while eliminating corrosion rings, as well as full Elemental Protection GEOMET coating on all non-mating surfaces to inhibit rust formation. GCX rotors are double disc ground to eliminate DTV issues, and feature OE style vane designs and machined non-friction surfaces to restore OE looks and performance. Sprayed as OEM, leaving friction surface uncoated; Pads bed in 10% faster than with fully coated surface; Wide application coverage; Double Disc Ground, Non-Directional Finishes 2007 - 2017 BMW X5, 2010 - 2017 BMW X6