Hello. Carro: cart, buit (noun): vaccuum. Are these guys using some vaccuum pumps in this experiment? This may come as a useful hint, I hope anyway. Link 1: "Vacuum Carts: The types of pumps we make are often a little heavy and often customers ask us if we can make a complete system for them that they can move from location to location around a plant.  We have produced a number of these types of systems from explosion proof liquid oxygen maintenance systems to just basic "vacuum source" types of systems.  We have made them with control panels, integrated gauges,  automated valves, various electrical requirements. ..". And link 2, which features a picture of it:"Heavy Duty Kit For 2" Vacuums. Designed for 2” vacuum carts. Kit includes an 18” commercial aluminum vacuum head, a 30’ stainless steel handle set, 50’ of 2” heavy duty vacuum hose, a 24” Pro wall brush, a Pro Leaf Rake, a Pro Skimmer, 50’ of 2” discharge hose, and clamps".
Hope it helps, chao :-)