Disclosed is a composite comprising: from about 50 wt. % to about 99 wt. % of a thermoplastic resin, wherein the thermoplastic resin comprises a polyester; and from about 0.1 wt. % to 15 wt. % of a carbon fiber filler, wherein the carbon fiber has a bulk density of at least 500 g/l and a volume electrical resistivity of less than 2,000 μΩ#cm, with individual filaments that have a length-to-diameter ratio of at least 300, wherein a 3.175 mm thick molded sample of the composite exhibits a Transmission of less than 15% of incident microwave radiation when observed according to a Free Space method, measured at frequencies of 75 to 110 GHz, wherein the combined weight percent value of all components does not exceed 100 wt. %, and all weight percent values are based on the total weight of the composite.