This is a low-friction brake sponge set for Mini 4WD race cars. It comes with 3 thicknesses. It gives a milder brake effect than the Red sponge set sold in Item 15492 JR Brake Sponge Set. Use the 3 thicknesses for different places on your Mini 4WD car! The 2mm sheet is a single piece to help differentiate easily between the 3 types.