Feature:1. Suitable for feel that the 42 stepper motor of the 3D printer is not strong enough, want to change to 57 or 86 motor.2. MKS CD expansion board can amplify the flow control signal, to avoid motor drive with optical isolation generate press on main IC.3. Ramps1.4, MKS Gen and other main board with five large motor drive can operate completely without pressure.4. Simple to use and easy to install, will offer you much convenience when you want to use.5. With MKS TB6600 4.5A large motor drive and MKS-Gen 3D printed motherboard.Specification:Condition: 100% Brand NewItem Type: Stepper Motor Driver Current Expansion Board Material: PlasticColor: As Pictures Shown4.5A Large Motor Drive: MKS TB66003D Printed Motherboard: MKS-Gen.Package List:5 x MKS CD Current Expansion Board 5 x 4Pin Bayonet Cable