TE Connectivity Positive Lock Connector Contacts - MK I 250 Series MK I 250 Series positive lock receptacle and flag style crimp terminals with reduced insertion force and snap action locking which accept a wire size range of 20 to 10 AWG. These Positive Lock crimp receptacles lock onto the mating tab terminals containing holes or dimples and make a mechanical 'snap' when correctly positioned and can only be removed when an integral depressor on the receptacle terminal is deflected.