(1R,3S)-3-(2,2-dichloroethenyl)-2,2-dimethylcyclopropane-1-carbonyl chloride, (1RS) cis-3-(2,2-dichlorovinyl)-2,2-dimethyl-cyclopropane-1-carbonyl chloride, cis-(2,2-dichlorovinyl)-2,2-dimethylcyclopropane carboxylic acid chloride, (+/-)-cis-permethric acid chloride, cis-3-(2,2-dichlorovinyl)-2,2-dimethylcyclopropane-1-carboxylic acid chloride,