It is an integral-structured metal coupling with a single spiral slit in the round material. A perfect integrated construction eliminates backlash. Maximum parallel offset 0.25mm and maximum angular misalignment 5deg. are allowed. The high-strength aluminum alloy material and alumite treated surface ensure a high-corrosion resistance. Two fastening methods can be selected, the set screw method ( ARM model) and clamp method ( ACRM model) . Normal torque 0.3Nm to 2.3Nm Drilled bores 2mm to 12mm Backlash Zero.