Abstract: A laser beam fanned into a triangular plane configuration by mirrors, succeeding additional mirrors focusing the laser curtain rays back onto a spot, the spot having a light detecting, electrical transmitting element such that a square wave pulse is generated as the laser timely sweeps the collecting mirror, a breach in the square wave occurring when the laser ray curtain is penetrated breaking a laser beam, thus said penetration being detected, a system of three laser curtains in X, Y, and Z coordinates, having means of traversing an object to be measured, determining the exterior of each of its six sides.