The device includes an inner conductor, a dielectric material, an outer conductor, a coupling spring, and a sliding sleeve. The dielectric material surrounds the inner conductor. The outer conductor surrounds the dielectric material. The sliding sleeve is slidably attached to the outer conductor. The coupling spring is attached to the outer conductor. The coupling spring includes a plurality of beam tines. Each beam tine includes a lever tine. An adjacent pair of beam tines is separated by a slot where the slot has a root. A first distance is defined from the root to an edge of the beam tine. A second length is defined from the root to a distal end of the lever tine. The first length is greater than the second length.