Provides torque transmision and alignment.Cost effective coupling design.Nickel-coated Iron is good in corrosive environments. Specifications:Product Name: Universal JointSize: 52mm x 12mm/2.03 inch x 0.47inch (L*D)Bore Diameter: 4mm to 4mm(0.16inch to 0.16inch)Material: nickel-coated ironNet Weight: 95gThread Size:M3Main Color: Silver Tone Package Content:2x Universal Joint