An electrical connector assembly includes an electrical connector and the pick-up cap assembled upon the housing of the electrical connector. A plurality of contacts are disposed in the housing and covered by the pick-up cap. The pick-up cap includes a pair of first side walls, and the housing includes a pair of first side faces corresponding to the pair of corresponding first side walls. Each first side face forms a pair of locking recesses. Each first side wall includes an operation section and a pair of latches. The operation section includes a cavity in the first side wall and a raised section above the cavity. Each latch includes a spring arm, and a hook located at the end of the spring arm and engaged within the corresponding locking recess. The latch is located within the boundary of the housing without extending beyond the corresponding side face.