Powell Elite wheels are precision cast with RollerBone’s best-rolling, tightest-gripping, longest-lasting urethane. This unique material was also developed by RollerBones and introduced in the early 1990’s. Like RollerBone’s art competition wheels, this material has been copied but not duplicated. This technology costs a little more but if you need the ultimate in roll, grip and wear, Bones roller skate wheels are the wheel for you.