they are electric pumped...like a trolley ......only this one is half the size and you wear it on your back...like a rucksack. We have one...though I don't use it..I found it uncomfortable to wear....the Boss said to put it on a shopping trolley (little old lady one)...but to be honest, you may as well have an Omnitrolley and extend the hose to the pole...that's what I did anyway...