Provides torque transmision and alignment.Cost effective coupling design.Nickel-coated Iron is good in corrosive environments. Specifications:Product Name: Universal JointSize: 35mm x 16mm/1.38in x 0.63in (L*D)Bore Diameter: 8mm to 10mm(0.31in to 0.39in)Material: nickel-coated ironThread Size:M4Main Color: Silver Tone Package Content:2 x Universal Joint