Check the listing for details. 2PCS Boat Car Shaft Coupler Motor connector Universal Joint Coupling. Condition: New. Listed at 4.96 USD. Feature: Made of satinless steel,durable. Fitment: Brush-less motor RC boat use Ideal accessories for RC Model motor, such as airplane boat model. Material:Metal Color:Silver Specification: 3*4mm: Side hole threads: M3 Top Tight Size:M3 Hole Diameter:4mm and 3mm Outside Diameter:9mm Overall Length:23mm Dimension:23 x 9mm/0.91 x 0.35"(L x Dia) 4*3.175mm: Side hole threads: M3 Top Tight Size:M3 Hole Diameter:4mm and 3.175mm Outside Diameter:9mm Overall Length:23mm Dimension:23 x 9mm/0.91 x 0.35"(L x Dia) 4*4mm: Side hole threads: M3 Top Tight Size:M3 Hole Diameter:4mm and 4mm Outside Diameter:9mm Overall Length:23mm Dimension:23 x 9mm/0.91 x 0.35"(L x Dia) 4*5mm: Side hole threads: M3 Top Tight Size:M3 Hole Diameter:5mm and 4mm Outside Diameter:11mm Overall Length:23mm Dimension:23 xFeature: Made of satinless steel,durable. Fitment: Brush-less motor RC boat use Ideal accessories for RC Model motor, such as airplane boat model. Material:Metal Color:Silver Specification: 3*4mm: Side hole threads: M3 Top Tight Size:M3 Hole Diameter:4mm and 3mm Outside Diameter:9mm Overall Length:23mm Dimension:23 x 9mm/0.91 x 0.35"(L x Dia) 4*3.175mm: Side hole threads: M3 Top Tight Size:M3 Hole Diameter:4mm and 3.175mm Outside Diameter:9mm Overall Length:23mm Dimension:23 x 9mm/0.91 x 0.35"(L x Dia) 4*4mm: Side hole threads: M3 Top Tight Size:M3 Hole Diameter:4mm and 4mm Outside Diameter:9mm Overall Length:23mm Dimension:23 x 9mm/0.91 x 0.35"(L x Dia) 4*5mm: Side hole threads: M3 Top Tight Size:M3 Hole Diameter:5mm and 4mm Outside Diameter:11mm Overall Length:23mm Dimension:23 x 11mm/0.91 x 0.43"(L x Dia) 5*5mm: Side hole threads: M3 Top Tight Size:M3 Hole Diameter:5mm and 5mm Outside Diameter:11mm Overall Length:23mm Dimension:23 x 11mm/0.91 x 0.43"(L x Dia) 4*6mm: Side hole threads: M4 Top Tight Size:M4 Hole Diameter:4mm and 6mm Outside Diameter:11mm Overall Length:23mm 5*6mm: Side hole threads: M4 Top Tight Size:M4 Hole Diameter:5mm and 6mm Outside Diameter:11mm Overall Length:23mm 6*6mm: Side hole threads: M4 Top Tight Size:M4 Hole Diameter:6mm and 6mm Outside Diameter:11mm Overall Length:23mm 5*8mm: Side hole threads: M4 Top Tight Size:M4 Hole Diameter:5mm and 8mm Outside Diameter:14mm Overall Length:35mm 6*8mm: Side hole threads: M4 Top Tight Size:M4 Hole Diameter:6mm and 8mm Outside Diameter:14mm Overall Length:35mm 8*8mm: Side hole threads: M4 Top Tight Size:M4 Hole Diameter:8mm and 8mm Outside Diameter:14mm Overall Length:35mm 8*10mm: Side hole threads: M4 Top Tight Size:M4 Hole Diameter:8mm and 10mm Outside Diameter:16mm Overall Length:35mm 10*10mm: Side hole threads: M4 Top Tight Size:M4 Hole Diameter:10mm and 10mm Outside Diameter:16mm Overall Length:35mm Package Include: 2 x Alloy Universal Joint Shaft Coupling Motor Connector