Mini 4WD Gear Lightweight Hole Drilling Jig for Response Improvement "Counter/Spur Gear" - It's important to drill holes evenly! By drilling holes (6 places) in the counter gear and spur gear, you can reduce weight. Response will also improve. Therefore, it is important to drill holes evenly. By using this jig, you can drill holes evenly. Please use a 2mm drill for drilling. This listing is for the processing jig tool only. Please prepare a 2mm drill, fixing screws, and shaft. How to use it is very easy, please purchase only if you understand. This product is manufactured using a 3D printer. There are no problems with its use, but the color may differ from the image or the shape may be slightly different, please understand. If you contact me, I can combine shipping with other items I have listed, so feel free to ask. Made by "Shimizu Seisaku Repair Workshop"