An electrical connector includes a base with a number of contacts, a cover pivotally mounted to the base, a pair of supporting components for mating with the cover and a pair of rail brackets for mating with the base. Each supporting component is pivotal between an opening status and a closed status relative to the base. The base is slidable relative to the rail brackets along a front-to-back direction. The cover and the pair of supporting components are mateable with each other in condition that one of the cover and the pair of supporting components pivots clockwise while a remaining one of the cover and the pair of supporting components pivots anticlockwise.