Infrared SED of the nebula M1-67 around the Wolf-Rayet star WR 124 from color-corrected photometric measurements from IRAS and Herschel (PACS and SPIRE) space missions. The best result of the 2-Dust model fitting is illustrated (solid line). It was achieved by considering two populations of dust grains (dashed lines), a population of small grains with radii from 0.005 to 0.1μm, responsible for the emission at λ< 40 μm and a population of large grains with radii from 2 to 10μm, responsible for the infrared SED at λ> 70 μm. Data at λ< 20 μm are not considered in the fit.