Ergonomic grip with push button that activates the stop-and-go mechanism Magnetic clamping rail with holes for a paper margin Crafted from impact proof plastic and is perfect architects, artists, designers and builders Ensures stability and accuracy of drawings with anti-slip protection on the underside, an additional locking mechnicsm, permanent gliding bolts and a corner clamp Get accuracy when drawing with built in features such as a protractor with inverse scale, compass plotting scale and a graduation with markings format & paper margin