Durable material: the centre punch is made of hardened chrome vanadium steel, which can withstand heavy impact. It is wear and rust, which prolong the life of the stamp. Easy positioning: the automatic punch uses the impact force of an internal spring for quick positioning. Adjustable: the automatic spring loaded grain is small and easy to carry. The red adjustable impact cap can increase or decrease the impact force. You can easily adjust the cap tightness clockwise or counterclockwise to achieve the desired depth. Widely used: the automatic grain punch is suitable for materials such as wood, glass, iron, ordinary steel, etc. Quantity delivered: 2 pieces Package Contents: Only the above package contents, excluding other products. Size: 13cm (Reminder: The size is measured manually, please allow 1-2 cm measurement error) Colour: Black (Due to different monitors and lighting effects, the actual color of the item may be slightly different from the color shown on the picture.