Spherical Sealing Technology Front CV Seal (D2777) by RCV Performance®. Patented Spherical Sealing Technology provides much greater resistance to punctures and tears than a rubber CV boot. If you’re looking for constant velocity (CV) joints and components to handle hard-core off-road abuse, RCV Performance joints are just the ticket. They are engineered to overcome the strength and binding issues associated with a universal jointed axle shaft.