Dual purpose, it comprises a 50 mm diameter, plastic or AI. pulley on a metal boss 20 x 20 x 110 mm long provided with a hole and a clamping screw to accommodate rods upto 13 mm diameter. Tapped holes to fit the pulley on to the boss with its axis of "rotation in any of the three planes. In addition to rod mounting facility, countersunk holes are provided so that board clamp can e attached to convert it into board/table mounting type. (a) AIuminium (b) Plastic