Abstract: A holder includes a first clamp and a second clamp, the first clamp having a first extension and the second clamp having a second extension, and gripping means having an opening defined therein for receiving the first and second extensions. The opening within the gripping means is of variable size so as to permit rotation of the first and second clamps when the opening is not constricted and to prevent rotation of either the first or second clamps when the opening is constricted, means also being provided to vary the size of the opening within the gripper means. Frictionless washers are interposed between the gripping means and the clamps and the extensions are spaced from each other, even when assembled, so as to facilitate the angular adjustment of the clamps and the workpieces held thereby, the stable support of the device nevertheless being maintained due to the interaction between the gripping means and the clamp extensions.