1. 2-in-1 Functionality: Caliper type ballpoint pen combines the convenience of a ruler and the practicality of a pen. Enjoy the versatility of using it as both a measuring tool and a writing instrument. 2. Durable and Replaceable: Our push-button mechanism makes it easy to disassemble and replace the ink , ensuring long-lasting use. With its sturdy plastic construction, multifunction vernier is built to withstand everyday wear and tear, providing value for your money. 3. Multiple Pen Color : For roller ball pen, you can choose between black or blue ink cartridges to suit your preference. Whether you need to take notes, draw diagrams, or mark measurements, we've got you covered. 4. Precise Measurement Range: With a measurement range of 0-100mm, stationery portable tools allows for accurate and meticulous measurements in applications. precision in your work every time. Please note: the physical slightly color or difference, does not affect the use, please do not mind, thank you! Can be used as a ruler or write, with black/blue refills available PushType ballpoint pen, easy to disassemble, replaceable refill, convenient for long-term use. Size: 0-100mm/0-3.9in : A: black core Colour:Silver Material:plastic Package Contents: 50 x Vernier Caliper Pen 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.