An easy way to insert the Retrac connector is to ensure the brass tabs are within the connector (not expanded) and to lift the ring to allow the “square” piece to rotate freely. Firmly push the connector down to the bottom of the inner trac, rotate the square piece to fall in place (it is actually narrower on one side to fit in the channel properly) and twist the ring, which will in turn lock the connector in place and expand the brass pads.