Size :L25xD20mm 5mm to 8mm Color :Silver Material:Aluminum Alloy High Quality: Made of aluminium alloy material, light, anti-oxidant, and anti-corrosive, delicate CNC cut with outstanding appearance, high precision fine workmanship, long service life Function: Used for connecting the driving shaft and the drived shaft of model motors, can convey the driving force steadily in the precise coaxiality. Use: Commonly used for shafts that transmit motion, and widely used for DIY model, such as 3d printer , car or boat etc. as connector for different parts as joint connector Package:2 x Flexible shaft coupling 1x Allen Key Weight : 17g/pcs