EKG caliper measuring tool set: you will get 2 EKG calipers with a scale coat, and 2 transparent ECG rulers, which can be applied to measure ECG waveform The EKG caliper pen has a clip that can be easily fixed to the nursing uniform Adjustable and Convenient: which is convenient to carry in the pocket The needle tip is fixed with screws, and the length of the 2 needles can be adjusted The 2 corners are fixed with screws outside, which is convenient to adjust the tightness of the 2 corners and Portable: which can be suitable for rapid basic ECG measurement on the paper and screen of patient monitor defibrillator Also suitable for routine use and emergency It has the advantages of light weight and small volume Reliable and reusable: the transparent ECG ruler is made of large-scale transparent plastic, which is reliable and has a protective sleeve for longer service life The 2 legs of the ECG calipers for nurses , which is reliable to use, wear-resistant and not easy to blister Thoughtful gift: the ECG calipers measuring tool for nursing is a thoughtful your friends who are nurses or nursing students, which is a practical them Please note: the physical slightly color difference or difference, does not affect the use, please do not mind, thank you! Material: MetalandPlastic colour: blackandpink Package Contents: 2 x ECG Sub-Gauges 2 x heart rate rulers 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.