My Rainbow Slalom GBC module consists of two parts (plus a new ball bucket to collect the test run). The two halves have separate for ease of transport, but fit together quickly with a couple of Technic beams joining them at the bottom for stability. Its unput is based on the very reliable Brickworld 2018 ball pump, which has been extended to reach about 20 bricks above the input hopper. The diagonal slope then feeds into a brick built slalom module which brings the balls zig-zagging back down to output level.