Features 1、Steel Material: Made of premium steel material, this bore coupling is strong and sturdy, corrosion resistant and possesses a long life span. 2、Fine Workmanship: These bore couplings have clean and smoothly edges, perfectly machined, and not easily deformed under pressure. 3、Easy Installation: Comes with screw holes and set screws, you can easily install the bore coupling and put it into use. 4、Wide Application: These bore couplings are widely used in the scenarios of motor, hardware, mold and mechanical transmission. 5、Package Includes: There are 5 bore couplings, 20 set screws and a wrench that they can meet your use and replacement needs, very practically. Item Type: Bore Coupling Material: 45# Steel Color: Silver Product Length: Approx. 22mm / 0.87in Product Outer Diameter: Approx. 14mm / 0.55in Inner Diameter of Product: Approx. 8-8mm/0.31-0.31in Side Hole Diameter: Approx. 4mm / 0.16in Applicable to: Scenarios of motor, hardware, mold and mechanical transmission. Package List 5 x Bore Coupling 20 x Set Screw 1 x Wrench