A device for delivering energy to tissue, comprising:an inner conductoran outer conductor (1260) coaxially disposed about at least a portion of the inner conductor, the outer conductor including a distal portiona dielectric material disposed between the inner conductor and the outer conductor anda sleeve member (1220, 1320) coaxially disposed about at least a portion of the outer conductor and movable relative to the outer conductor to selectively expose the distal portion of the outer conductor.
