Abstract: An improved track lighting apparatus wherein an electrical connecting device connects a circuit element to an electrical power track. The track carries a plurality of electrical conductors axially extending along the rail like structure of the track. There is a continuous opening which extends axially in the outer wall of the track defining a slot with laterally spaced walls which contain a channel extending axially along the length of the track. The electrical connecting device is insertable into the slot at a preselected position along the track. The connecting device has a housing made of an insulative material and carries first and second electrical contact members which are biased by a spring made of a nonconductive material. The housing carries a flange which is adapted for insertion into the track channel to form a releaseable lock.