Are you sure your asthma is well controlled? Don't guess - use a PEAK FLOW METER. Ths device can tell you if your lung function is good or not and thus, how well your asthma is controlled. The trust is passionate about this and we are campaigning to get everyone with asthma using a PEAK FLOW METER AND DIARY. Join us now. If you don't have one -e-mail us and we will send you one along with a diary.