1. Switch on/off magnetic base to move at any time without reaction force, avoiding damage to the gauge and working desk. 2. The base is equipped with a permanent alloy magnet and a central locking mechanism with anti-loose springs. 3. Made of highly wearproof Metal, the shell is chrome-plated to achieve rust-proof, and beautiful results. 4. Concise structure, easy to use and maintain, high sensitivity, stable and reliable. 5. Flexible arm can be fixed at any angle, easy and quick to use, widely used in mechanical correction and technical measurement. Colour:red Material:Metal Size: 300mm Package Contents: 1 x watch stem Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.