This is a pinion gear used in Plarail wheels, etc. It has 14 teeth. Please make sure you have the correct one. The hole diameter is 2.4mm, and it can be installed on Plarail wheels without modification. Since the Plarail wheel axle is 2.5mm, it will be a press-fit, and it will be securely attached. However, it is easier to install with tools such as a vise. The width of the original gear may be about 4mm, while this product is 5mm. You may need to shave off a little of the width to use it with the chassis in the second photo. It can be used as is in the motorized vehicles in the third and fourth photos. The motorized vehicle of the diesel locomotive in the fifth photo is a bit tight as is, but it worked. You may need to shave off a little. It can also be used for other general purposes. Gear Information Module: 0.5 Pitch circle diameter: 7mm Total length (width): 5mm Hole diameter: 2.4mm Diameter: Diameter: 8mm *The diameter is the length from the tip of the gear teeth to the opposite tip. To offer it at a low price, it will be shipped by regular mail. Please check the self-introduction section for details about regular mail. If you want more than 9 pieces, please consult in the comment section. We also sell 10-tooth and 12-tooth gears, so please take a look. Additional gears are 20 yen each. We sell many other pinion gears. Please click the following tag: #PartsShopPinionGear