SMALL MASK USES - THE TUNNEL EFFECT - OF STRECHED - PRO LONGUE - DISCTANCES - IMAGINE - BENDING A 2 M LONG ROD / OR HOLLOW - THING - SUCH AS A PIPE - AND BREATH THAT AIR EASY AS THAT : NOTE THE 3RD FILE WICH SAYS DO NOT PRINT - IS ACTUALLY A POSITIVE OF THE NEGATIVE SPARED OUT IN THE MASK TO SEE HOW THE AIR FLOWS - ENJOY ! AND STAY HEALTHY !!! FRANCIS .