• Versatile Usage - Ideal for calculating length and distance in classrooms and professional applications. Features an optically clear acrylic body for easier and more accurate measuring.
• Thumbscrew Lock Mechanism - Use the thumbscrews to keep and adjust the angle you want locked securely in place at your desired rise, slope or angle.
• Includes Rise and Slope Graduations - Comes with premium hot-stamped graduations that will not rub off or wear with extended use, making this a reliable tool for many projects to come.
• Detailed Instructions Included - Helpful instructions are provided to simply guide even first time users on proper and efficient use.
• A Professional's Choice - Alvin has been the professional's choice for drafting tools and drawing supplies for over half a century. Since 1950, we have brought quality and value to our customers.

Proudly Made in Taiwan