A wood chipper with an air entrainment system. , stretching the film in the transverse andor longitudinal directions to make it breathable; it is also shown a plant for producing a breathable elastomeric polyolefin film and the use of a mixture of olefins, styrenic thermoplastic elastomers and filler to produce a breathable elastic film. When two such equipped devices come within proximity of each other, a direct non-network wireless communication link is established.