This trolley is designed for cases where vacuum outlets are far from patients and there's a need to use many canisters at a time. This can use four canisters at a time and can be arranged around the entire body of the center post. This is made with a setup that works with a swivel fitting to get the vacuum regulator to go up onto the top of the unit. The regulator can be rotated and four canister ports may be used to get any canister to work while other models are in standby mode or are being charged up.