An electrical connector with an insulative housing, a plurality of contacts retained in the housing, and a metallic shell secured to the housing. The housing includes opposite first wall and second wall and a pair of side walls to generally commonly a mating slot communicating with an exterior via a mating opening. The shell includes opposite first plate and second plate and opposite side plates to commonly form a receiving cavity above the mating opening. The opposite side plates further include a pair of downwardly extending securing sections retained inside of the housing. The opposite side plates further include a pair of oblique transitional sections respectively located at roots of the pair of securing sections and in the receiving cavity and proximate to the mating opening for guiding consideration.