The Vitalograph Peak Flow Meter is a simple and accurate way to measure lung function and monitor asthma. The device has easy to read colored management zones that have been set by Healthcare Professional. Accurate, compact, lightweight and portable. Robust and hard wearing. Features comfortable integral mouthpiece. Quickly read scale markers. Conforms to all peak flow standards including ISO23747:2007. Suitable for adults and children. Suitable for multi-subject use with Safeway mouthpiece. Note: Mouthpieces sold separately. A result of 100% is the asthmatics or users best. The yellow area will typically be set to start at 80% of the asthmatic's best while the red zone will usually start at 60%. Variability of PEFR of greater than 20% should alert the asthmatic to a possible asthma attack.When it comes to Fitness Testing equipment then look no further than McSport. We offer an extensive range of equipment that will cater to all your Fitness Testing needs.