tongue 712 projects from the corresponding side wall into the channel stem 713 may be spring biased and normally positioned as shown in the blocking position such that linear stop face of stop tongue 712 are positioned to prevent rj 11 insertion if an attempt is made to insert an improper rj 11 plug into plug receiving cavity 714 the plug body will not contact flared free end 711 will not push on stem 713 and consequently will be blocked by the linear stop face of stop tongue 712 if however a proper rj 45 plug is inserted into plug receiving cavity 714 the body of the rj 45 plug will contact flared free end 711 pushing it along with stop tongue 712 out of the way allowing full insertion thereof it will be appreciated by one of ordinary skill in the art that although in the illustrated exemplary embodiment mechanism 710 is shown separately attached onto for example a housing associated with molded stacked connector 700 it may be incorporated during fabrication into the molded receptacle itself or attached as a separate set of spring elements it should further be noted that although the view illustrated in fig7 allows only one side of the mechanism of the present invention to be seen a complimentary portion of the mechanism is preferably present on the other side of plug receiving cavity 714 as previously described the stacked connector of the present invention is not limited to a 1 u00d7.