Features: Crafted with thickened aluminum alloy material, this magnetic ruler offer reliable magnetic adsorption for accurate measurements. The strong magnetic adsorption and durable aluminum alloy constructions make this ruler a practical tool for precise measurements. Suitable for engineers, architects, designers, and students, this ruler caters to the measuring needs of various professionals. 3 easy-to-read vials made from durable, highly clear acrylic glass with smooth inner side and bright fluorescent liquid inside. Horizontal accuracy at 180°, vertical accuracy at 90°, all with a high degree of precision: ±0.029 = ± 1mm/m Specifications: Material:Aluminum Alloy Length:Approx.30cm/11.81'',40cm/15.74'',60cm/23.62'' Package Includes: 1x Spirits Level note: Please allow 1mm errors due to manual measurement. Due to the difference between different monitors, the picture may not reflect the actual color of the item.