RS Insulated Female Receptacle Crimp Terminals A range of insulated female receptacle crimp terminals made from brass with a copper sleeved barrel and flared vinyl insulation. These insulated female receptacle wire connectors are Color coded for use with different wire sizes including Mini Yellow 0.2 - 0.5 mm2 and accept a variety of tab sizes. Mini Yellow 0.2 - 0.5 mm2 Red 0.5 - 1.5 mm2 Blue 1.5 - 2.5 mm2 Yellow 2.5 - 6.5 mm2