ViaGasaFamido Robot Arm Kit, 4DOF Wood Robotic Arm Lightweight DIY Mechanical Arm sg90 Servo, Assembled for SNAM1500

The 4-DOF mechanical arm is a great multi-purchase learning experience for people interested in robotics. It comes with a little wrench for the nuts, but you would need to bring your own Phillips screwdriver as it is not provided. One of the aspects of the learning process is to build something from a visual reference, which only has a couple of pictures of a completed product, as the product doesn't come with a manual. However, the manual for the product is available on a different website, and you can follow the link provided in one of the customer reviews to access it. With that being said, there is one negative review that suggests that the product didn't work, and the return window had already elapsed.