Check the listing for details. 2pcs Model Car Shaft Coupling Motor Connector Alloy Universal Joint. Condition: New. Listed at 6.88 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:23Feature:Made of satinless steel,durable.Fitment: Brush-less motor RC boat useIdeal accessories for RC Model motor, such as airplane boat model.Material:MetalColor:Silver Specification:3*4mm:Side hole threads: M3Top Tight Size:M3Hole Diameter:4mm and 3mmOutside Diameter:9mmOverall Length:23mmDimension:23 x 9mm/0.91 x 0.35"(L x Dia) 4*3.175mm:Side hole threads: M3Top Tight Size:M3Hole Diameter:4mm and 3.175mmOutside Diameter:9mmOverall Length:23mmDimension:23 x 9mm/0.91 x 0.35"(L x Dia) 4*4mm:Side hole threads: M3Top Tight Size:M3Hole Diameter:4mm and 4mmOutside Diameter:9mmOverall Length:23mmDimension:23 x 9mm/0.91 x 0.35"(L x Dia) 4*5mm:Side hole threads: M3Top Tight Size:M3Hole Diameter:5mm and 4mmOutside Diameter:11mmOverall Length:23mmDimension:23 x 11mm/0.91 x 0.43"(L x Dia)5*5mm:Side hole threads: M3Top Tight Size:M3Hole Diameter:5mm and 5mmOutside Diameter:11mmOverall Length:23mmDimension:23 x 11mm/0.91 x 0.43"(L x Dia) 4*6mm:Side hole threads: M4Top Tight Size:M4Hole Diameter:4mm and 6mmOutside Diameter:11mmOverall Length:23mm5*6mm:Side hole threads: M4Top Tight Size:M4Hole Diameter:5mm and 6mmOutside Diameter:11mmOverall Length:23mm 6*6mm:Side hole threads: M4Top Tight Size:M4Hole Diameter:6mm and 6mmOutside Diameter:11mmOverall Length:23mm5*8mm:Side hole threads: M4Top Tight Size:M4Hole Diameter:5mm and 8mmOutside Diameter:14mmOverall Length:35mm6*8mm:Side hole threads: M4Top Tight Size:M4Hole Diameter:6mm and 8mmOutside Diameter:14mmOverall Length:35mm 8*8mm:Side hole threads: M4Top Tight Size:M4Hole Diameter:8mm and 8mmOutside Diameter:14mmOverall Length:35mm 8*10mm: Side hole threads: M4Top Tight Size:M4Hole Diameter:8mm and 10mmOutside Diameter:16mmOverall Length:35mm 10*10mm:Side hole threads: M4Top Tight Size:M4Hole Diameter:10mm and 10mmOutside Diameter:16mmOverall Length:35mm Package Include:2 x Alloy Universal Joint Shaft Coupling Motor Connector