["Description:\r\nbrand new and high quality\r\nOptional type: set, SG90 set(as your choose)\r\nMaterial:Acrylic \r\nColor:Black\r\n\r\nDifference between and SG90: \r\n: Metal gear,steering engine,development board (Original version)\r\nSG90: Plastic gear, steering engine development board (China version)\r\n\r\nDIY value\r\nLearning potentiometer control servo\r\nLearning serial port control servo\r\nUnderstand the control principle of automated robotic arms\r\n\r\nThis is a classic 4-DOF machine that has been around for a long for time and is inspired by industrial robotic arms. This is an economical, powerful and easy to use robotic learning kit. The kit is suitable for use in the maker space, college students, and middle school students. The control board adopts the international version of the original UNR 3, and there are many learning materials on the network for easy learning and use.\r\n\r\nAbout control methods\r\nThe control method is also very simple, with four knobs to control the movement of each potentiometer, anyone can operate. After connecting the computer with USB, you can send commands through the serial port to control the movement of the servo. It is also for other computer control software, and also supports writing programs to perform fixed and repeated actions.\r\n\r\nAbout assembling\r\nThis product expansion board is shipped as a spare part and needs to be soldered by yourself. The assembly of acrylic parts requires a certain amount of patience, we provide a complete graphic tutorial for everyone as a guide. The original knob control program has been burned.\r\nQuantity: 1 set\r\nNote:\r\nTransition: 1cm=10mm=0.39inch\r\nNo retail package.\r\nPlease allow 1-2cm error due to manual measurement. pls make sure you do not mind before you bid.\r\nDue to the difference between different monitors, the picture may not reflect the actual color of the item. Thank you!\r\n\r\nSG90 Package includes:\r\n1 set x Acrylic cutting parts + fixing screws\r\n1 xdevelopment board (China version)\r\n1 x Potentiometer control board (need to be soldered by yourself)\r\n1 x 5V2A power adapter\r\n4 x SG90 servos(other accessories demo in the picture is not included.)\r\n\r\nor \r\n\r\n: set Package includes:\r\n1 set x Acrylic cutting parts + fixing screws\r\n1 x development board (Original version)\r\n1 x Potentiometer control board (need to be soldered by yourself)\r\n1 x 5V2A power adapter\r\n4 x servos(other accessories demo in the picture is not included.)"]