of threads 27 locate directly below receptacle 25 within a reduced midsection area of passage 23 the lower portion of passage 23 is of larger diameter than the threads 27 this results in a downward facing shoulder 29 located within the lower portion of passage 23 the upper end of threads 27 is a selected distance below receptacle 25 resulting in a smooth pilot bore 28 in passage 23 immediately above threads 27 each female insulator 21 has an external flange 31 that locates within an enlarged portion at the upper end of hole 19 a retaining ring 33 locates above flange 31 to secure each female insulator 21 to the female body 11 retaining ring 33 may be secured to base 17 by fastener means such as screws not shown a connection sleeve 35 secures within each female insulator 21 connection sleeve 35 is a metallic conductor connection sleeve 35 has external threads 37 that screw into internal threads 27 in the female insulator 21 the upper end of the external threads 37 locates at the lower end of pilot bore 28 a smooth cylindrical portion of connection sleeve 35 fits tightly in pilot bore 28 with the upper end of connection sleeve 35 being flush with the bottom of receptacle 25 connection sleeve 35 has a receptacle 39 within it that has a closed bottom connection sleeve 35 also has a socket 41 on its lower end one of the electrical wires 43 will insert into socket 4 and will.