"Max Flow with 1.2?m filter: 20 lm-1 Max Flow, free air: 30 lm-1 Dimensions: W 200 x H 130 x D 216 mm Supplied with free battery and battery charger For use at higher flow rates but still compact in size. Utilises our electronic flow control circuit to maintain the set flow rate to within �5%. Maximum run period is five hours continuous use. Flow rate is easily adjustable with a small screwdriver, one of which is supplied with each unit. The SP 021 can be fitted with the quick release mast, if required (see SP014)"