7 speed freewheel (shimano type splinded) Count the gears on your old freewheel and get the same here. The freewheel is the part on your bike that the chain wraps around on your rear wheel. As one pedals the freewheel engages and turns the rear wheel. When one stops to pedal the freewheel allows you to coast without the pedals turning. If you pedal and go nowhere you may need a new freewheel, or if you stop pedaling and the pedals keep turning you may need a new free wheel. The old freewheel needs to be removed with a special tool before the new one can be threaded on to your wheel. Please call us if you have any questions.