Provides torque transmision and alignment.Cost effective coupling design.Nickel-coated Iron is good in corrosive environments. Specifications:Product Name: Universal JointSize: 23mm x 9mm/0.91in x 0.35in (L*D)Bore Diameter: 4mm to 4mm(0.16in to 0.16in)Material: nickel-coated ironNet Weight: 14gMain Color: Silver Tone Package Content:2 x Universal Joint