A clamping device for an external fixation system includes a first clamp having an opening for receiving an external fixation element, the first clamp having an axle seat. A first base component includes a concave first surface and a second surface facing away from the first surface. The concave first surface is in selective engagement with the clamp. A swivel element comprises an axle component and a post component. The axle component is disposed on the axle seat of the first clamp. The post component extends from the axle component and has a length sized to extend from the axle component through a second external fixation clamp. The post component is arranged to swivel relative to the axle seat. Methods are also disclosed.