the sidewalls 12 and 13 to communicate with the corresponding gaps and each chamber 111 has a terminal passageway 110 adjacent to the step portion 17 to receive a terminal 2 the sidewall 12 has an inclined surface 120 and the sidewall 13 is of rectangular a pair of grooves 102 are depressed in inner surfaces of the sidewalls 12 and 13 and extend backwards from the enlargement portion 16 to the stopper wall 18 the stopper wall 18 extends vertically and connects the grooves 102 and the terminal passages 110 the housing 1 defines a receiving cavity 101 at its center to receive a complementary connector not shown the receiving cavity 101 extends backwards from a front surface of the front portion 10 to the stopper wall 18 and communicates with the grooves 102 the top wall 15 has a rectangular indentation 150 and a channel 151 which extends forwards from the projection 170 and communicates with the receiving cavity 101 the bottom wall 14 stands in a horizontal surface and has a pair of hollows 140 the pair of terminals 2 have the same configuration and each has a soldering portion 21 a mating portion 22 and a z shaped connecting portion 23 the.