Empire's professional 400mm True Blue laster Etched Framing Square has been designed with accuracy, readability & durability in mind. High Visibility Laser Etched Graduations provide twice the accuracy over standard stamped squares & will never wear, scratch or fade away. over time Large and easy-to-read high visibility markings with 2mm increments make for easier readability. Constructed from a durable and lightweight, heavy-gauge aluminium users can rest assured the 400mm True Blue Laser Etched Framing Square won't rust or corrode or bend. Included ARC SCRIBE is designed for precision radius layout & markings & a common conversion table on the back of the Square is ideal for common applications such as rafter cuts.