After my trolley died on me last week, decided to use backpack for all my work. ordered the basic wcw1 from window cleaning warehouse for 98 pound. Got phone call saying it was out of stock and got upgraded for no extra charge to the next modal which came the following day, Great service. Released me from the dragging the hose around, but boy does it make your shoulders ache if you have it on your back for too long. Really enjoyed using it and even though they have a small pump didnt notice any differences.