ITEM NAME:6 DOF Robot Arm Potentiometer Servo Knob Control Board Expansion Board Description: 100% Brand New and High Quadlity. This Potentiometer Servo Knob Expansion Board Module for accessories kits. Board Knob Can Control Servo, easy to operate. Also for controlling 6 servo. This is unfinished module kits, need to weld and assembly it. Specification: Matreial: Plastic Color: Blue Size: approx. 6.8x5.3x0.1cm/2.67x2.09x0.04inch. Package Includes: 1 Piece Servo Expansion Board SKU: DMO0012527457042101.1 Piece Servo Expansion Board. People always bought together with. This is unfinished module kits, need to weld and assembly it.