Provides torquae transmision and alignment.Cost effective coupling design.Stainless steel is good in corrosive environments. Specifications:Product Name: Universal JointSize: 13mm x 7mm/0.51in x 0.28in (L*D)Bore Diameter: 3mm to 3mm(0.12in to 0.12in)Material: Stainless SteelNet Weight: 9gThread Size:M2Main Color: Gold Tone Package Content:3 x Universal Joint