Zeberoxyz 2PCS 10mm to 10mm Aluminium Plum Flexible Shaft Coupling Diameter 20mm Length 25mm Connector Flexible Coupler for 3D Printer CNC Machine and Servo Stepped Motor（10x10mm） D20 L25 10x10mm Style:10x10mm They are easy to install

They are easy to install

At sometime or another you may run out of pins on your Arduino board and need to extend it with shift registers

only use the hammer will damage the screws

The travel carrying storage case is equipped with two elastic bands

Zeberoxyz 2PCS 10mm to 10mm Aluminium Plum Flexible Shaft Coupling Diameter 20mm Length 25mm Connector Flexible Coupler for 3D Printer CNC Machine and Servo Stepped Motor（10x10mm） D20 L25 10x10mm Style:10x10mm They are easy to installZeberoxyz 2PCS 10mm to 10mm Aluminium Plum Flexible Shaft Coupling Diameter 20mm Length 25mm Connector Flexible Coupler for 3D Printer CNC Machine and Servo Stepped Motor10x10mm Product Specification: Product Name: Shaft Plum Coupling Type: Plum Shaped Shaft Usage: 10mm to 10mm 0. 39inch to 0. 39inch Size: L25mm x D20mm 0. 98inch x 0. 79inch( LD) Material: Aluminum Alloy,Polyurethane Main Color: Silver Tone,Red Weight: 30g The shaft couplers are