Provides torque transmision and alignment.Cost effective coupling design.Nickel-coated Iron is good in corrosive environments. Specifications:Product Name: Universal JointSize: 18mm x 8mm/0.71inch x 0.31inch (L*D)Bore Diameter: 2mm to 2.3mm(0.08inch to 0.09inch)Material: nickel-coated ironNet Weight: 15gThread Size:M3Main Color: Silver Tone Package Content:2 x Universal Joint 4 x Screws