uxcell 3mm to 4mm Copper DIY Motor Shaft Coupling Joint Connector for Electric Car Toy Product Name: Coupling Joint; Material: Copper Size: 20mm x 9mm/0.8" x 0.35"(L*D); Type: 3mm to 4mm Side Thread Diameter: 2.5mm/0.1"; Fixed Type: Clamp Main Color: Gold Tone; Net Weight: 9g Package Content: 1 x Coupling Joint, 5 x Screws, 1 x L Bar