|These double lock drawing boards are of an ergonomic design for easy, comfortable working. They have a parallel drafting ruler with double-sided scale, A double Stop-and-Go locking system to lock the drafting ruler any position on the guide way. Featuring Two guide ways for smooth and easy to move positioning of the drafting ruler. Both sides have a paper clamp to fix or loosen the paper. Includes a scale with needle hole for precise compass radius setting. These drawing boards are made of high-impact plastic material making them light weight and extra stable.