The 5mm to 5mm flexible couplings are manufactured with high-quality aluminium which minimum backlash possible. These aluminium couplings are generally used to connect your driving shaft with the driven shaft. It is able to achieve this in the most efficient way possible while avoiding any misalignment. Flexible shaft couplers used in small CNC machines and 3d printers such as Prusa i3 or ord bot. Flex capability of the coupler removes stress when shafts are not aligned perfectly.