The Pulley Base Pack contains pulleys of different sizes and assorted rubber belt size, and is included in all VEX IQ Starter Kits and Super Kits. (2) 10mm Pulley (2) 20mm Pulley (2) 30mm Pulley (2) 40mm Pulley (2) 30mm Rubber Belt (2) 40mm Rubber Belt (2) 50mm Rubber Belt (2) 60mm Rubber Belt (2) Tire (100mm Travel) Note:The base colour for the Pulley Base Pack (228-3508) is blue.