The POLOLU 30T Track Set is a versatile and self-contained track system with a total of 30 bright orange snap-together tracks. The set includes straight tracks, curved tracks, a dual speed switch, support beams and two crossing bridges. With the parts in this set, you can make a variety of track shapes and configure your track as a loop, a figure eight, or any combination you can imagine. The tracks measure 129mm (5.1”) long and are designed for 8mm, 5mm, and 3mm precision plastic wheels that can be used with 3 mm D-shaft and 4 mm D-shaft motors for custom robotics projects.