Equipped with 3 spirit vials, horizontally (180°), vertically (90°), and at an angle (45°).Aluminum frame construction to reinforce and prevent warping. With two precision-milled measuring surfaces on both sides. Plus heavy-duty, shock-absorbing rubber end caps. Featuring a V-groove that is designed to fit against round surfaces such as pipes. Specifications: Model no: TMT23086 Accuracy: 0.5mm/m Material Aluminium, Acrylonitrile butadiene styrene (ABS), Rubber Length: 30cm Thickness: 1.5mm v-shape slot for measuring objects with round surface