Robust board of unbreakable, non-warping material for durability The L-system, straight edge design allows drawing along the top edge of the straight-edge right down to the bottom of the sheet Parallel straight edge with Stop-and-Go mechanism for added stability One magnetic clamp strip with automatic hold-open and additional corner clamp for easy positioning and clamping the media Guide rails designed for permanently smooth, featherlight straight-edge movement; Media-size markings and viewing holes for checking the exact placement of the media.