The washboard section was a great hit when used on the official Mini 4WD track used in Japan's Mini 4WD Cup races in 2013. These parts are now available as a stand-alone accessory track product. The part creates a slight jump which can be placed on the track to add an extra challenge to your Mini 4WD racing. Contains: 2-5mm height sections (length:120mm, width: 49mm), and 2-10mm height sections (length: 120mm, width: 55mm). The washboard sections can be installed in pairs or individually. Material is included to attach to the track. Use with TAM69569-Mini 4WD Oval Home Circuit with Lane Change, and TAM69506 -Tamiya Racing Mini 4WD Japan Cup Junior Circuit.