3 an insulator mount 4 and a housing 5 the body portion 1 is with a seat 10 and a slot 11 at the bottom a first opening 12 at one side a second opening 13 at the other side and a notch 14 at the end side on the outer side of the body portion 1 there are two upper protuberances 15 and a raised elongated member 16 below the upper protuberances 15 the seat 10 is formed with a groove 17 and a hole 18 the first terminal 2 is provided with a lug 20 having a hole 21 at one end and a bi metallic strip at another end the lug 20 has a blade 25 extending therefrom further the first terminal is fixedly mounted in the body portion 1 by a screw 22 with the hole 21 of the terminal 2 aligned with the hole 18 of the body portion 1 and the blade 25 extending out of the first opening 12 of the body portion 1 in addition the bi metallic strip 23 has a silver contact 24 at the end the second terminal 3 is formed with a fixing portion having a silver contact 33 and a hook and a blade 35.