Quantity: One Piece Precise Measurements: To ensure accurate markings, our drawing tools can display metric and imperial values. Accuracy is 0.2mm. Material: Made of high quality brass, aluminum alloy and stainless steel, durable and long service life. Size: 21.7 x 5.95 cm (total length x maximum diameter); Measuring range : 0-12cm; Fine adjustment : 0.2mm. Anti-Roll Design: Prevents this marker from rolling on your workbench. It features a roll-resistant brass fence with 2 flat spikes on the head to prevent the countertop from rolling. Ease of Use: Dual-function balance, which can meet both straight and curved requirements. 59.5mm diameter, solid brass surface glides over the edge of the workpiece, with a pre-ground steel shank