Tamiya Mini 4WD Drive System (Gear Bagged) These are repair and spare parts. They can also be used for sorting, etc. There are 14 sets. If anyone wants more, please let me know in the comments and I will look for them. For single-shaft motors, 14 sets. When purchased from Customer Service, looking at the price of the assembly instructions, it costs 600 yen (each, metal fitting set + gear bag). I think it's a good deal. Thank you for your consideration.