The Cirrus™2 nebuliser has been designed to minimise the residual volume and reduce drug wastage. At a driving gas flow of 8 L/min, 74% of the volume output will be particles less than 5 microns in diameter with a mass median diameter (MMD) of 3.3 microns.   The Cirrus™2 Adult mask kit incorporates the Eco aerosol mask, this non-PVC mask reduces the environmental impact of this product compared with a conventional mask kit by 28%.