3MM Axle Spacers - Set of 8NEW! When precision axles alignment is required, we have the solution: Set consists of 8 fine molded axle spacers for 3mm diameter axles for Carrera(R) 1 24 scale cars and 1 32 scale slot cars equipped with 3mm axles. Set includes the following sizes: 2 spacers, 0. 8mm wide, 2 X 1. 2mm and one each in sizes 1. 8mm, 2. 2mm, 2. 8mm and 3. 2mm. All attached in one common carrier twist or cut off with side cutters or sharp knife.