Thankfully there are two types of cartridges, flow and a non-flow control type of cartridge. The difference is that the flow type has a control level to stop and continue flow while with the non-flow, there is no control level included. So if you’re new to using CO2 cartridges, you should consider buying the non-flow instead of the latter. Your chances of wasting the gas entirely are minimal if you do not position the bicycle tires properly when filling with the gas.