we have 2 fitted with peter fogwill brushes they are great for pulling out for buildings with say about 40 upper windows to rear of building, which has grass and the parking facility to the vehicle or trailer outstreatches the hoses
typical situation is hospitals, usually have restricked parking areas
jinky hope this helps
on domestic they can be used like on a trolley we use then for windows on roofs at front of houses and easily lifted for the backs, we had our trolleys specially made
with cage for backpacks you just slip them in without having to tie them to the sack trolleys, a quick lift out and they are on your back
hope this helps jinky