Package Includes: You receive a EKG caliper and 1 transparent ECG ruler, suitable for electrocardiogram drawing, which is a nice supply for school and hospital Quality Material: ECG caliper is made of quality stainless steel material, and the ECG ruler is made of plastic, reliable and strong, not easy to rust or deform, you for a long time Ruler Design: There is a scale design on the protective cover and the measurement range is 0-6cm/0-2.4 inch. EKG ruler measures . 24cm/9.4inch in length, perfect for measurement reference Portable to Use: EKG caliper measuring tool can adjust to the desired length to meet your needs, the compact appearance can be stored and carried anywhere you like Wide Application: The EKG caliper measuring tool ia great for nurses, students and doctors, which can be applied to measure the proper result and data, a practical gift for them The EKG caliper pen has a plastic clip that can be easily fixed to the nursing uniform, and small size also can fit pockets and pencil cases well, easy to carry and use anytime, anywhere! Product name: EKG Calipers and EKG Ruler Combination Set Size: 1.7x11.4cm/0.7x4.5inch Ruler: length: 24cm/9.4inch, width: 5cm/2.0inch, thickness 0.12cm/0.05inch Colour:As Shown Material:plastic Package Contents: 1 set x ECG Caliper Measuring Tool 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.