Easy to use with a detachable grip; lightweight and comfortable to hold, making it a reliable drawing aid for teachers. Clear scale for easy measurement; the ruler features a clear scale that is easy to measure and read, suitable for chalkboards, whiteboards, erase boards, and more. Math teacher aid for classroom use; a large straight ruler ideal for drawings and mathematics instruction, suitable for classroom, school, or office settings. Durable PP material; made from high-quality PP material with high flexibility, wear-resistant, not easily deformed, and featuring a smooth surface that does not scratch the hand. Use scenarios: - Draw precise straight lines and diagrams in math class on whiteboards or chalkboards. - Prepare worksheets, charts, and posters with accurate spacing and alignment. - Use in classrooms or offices for marking measurements and organizing content on large charts and boards.