Number (N)ine SS2000 ‘Extra Heavy’ Nomex Sunday Mechanic Work Pants, size 4. These classic work pants feature an innovative Nomex fabrication, a fire resistant fabric developed by DuPont Racing in the 1960s and now commonly used in many types of protective gear. The iconic design is finished with red piping and embroidered patches. Measures 31.75 waist 9 front rise 12.5 back rise 28.5 inseam 9 leg opening