An articulation element consisting of a plurality of adjustable jaw pairs for the purpose of fixating the relative position of coupled bars and/or bone pins of an external bone fixator. Each of the adjustable jaws consists of a pair of hemispherical jaw elements contained within a spherical housing. A passage is eccentrically arranged through the jaw elements to accept the pin or bar. The jaw elements have interposed between them a spring element that serves to bias the jaw elements in the closed position. Pins serve to provisionally lock the jaw elements in the closed position. Spring loaded buttons act to release the pins thereby allowing the jaw elements to open accepting the pin or bar. The jaws are attached in a back to back fashion through the use of a threaded collar which acts as a turnbuckle pulling the jaws together when tightened.