Abstract: An alignment, marking or positioning device is provided by a base, a chain and a retractor. The base is concave on a portion of its lower surface and the chain is rotatably attached to the base of the corner adjacent to the surface. On the other side, the base has a slotted arcuate finger. A hook extends downwardly through the slot and engages the chain when it is placed around a shaft, pipe, chuck or the like. The hook extends through the slot, a semi-circular anchor means which slides within the finger and is snugged by a retractor which may be a knurled knob where a threaded hook shaft is utilized or some form of a camming device. The base is provided with a means for attaching gauge holders, scribes, positioning devices, etc.