This set includes 2 black ECG caliper, and a set of electrocardiogram rhythm explanation cards (made of PVC materials); these valuable tools can help you understand complex heart rhythm Our products include 3 electro -image caliper measurement tool cards; these double -sided cards can support the learning rhythm, and at the same time as a fast reference guide in a harsh working environment; Suitable for those who learn the basic heart rhythm of advanced ACLS certification; this set of caliper measurement tool EKG is a secret weapon for many ECG courses; whether you are an experienced nurse, you undoubtedly want them. EKG standard design is easy to transport, practical, suitable for daily and emergency use; its compact and light design is more suitable for patients to monitor the paper or the electrocardiogram on the screen quickly measured;Product is portable and easy to use Nursing uses an ECG card ruler measurement tool; these cards means that the speed of learning be easier, you can better cope with the problem of complex heart rate; this tool is an intimate gift for the nurse; the practical gift for them; Reliable and Reusable ECG Calipers:The ECG rulers in this set are made of plastic material and have a long service life. In addition, the legs of the EKG calipers are made of metal, which is and wear-. These reliable and reusable ECG caliper measuring tools stand up to regular use. Adjustable and Convenient ECG Calipers:The overall length of this flexible 4.5 inch /4.5 inch ECG caliper measuring tool is not only pocket-friendly, but can also be adjusted to your preference. It features a fixed needle and adjustable corner length. These ECG calipers are an invaluable adjustable tool for anyone in the medical field. Size: ECG calipers are 4.5 inch /11.5cm Colour:As Shown Material:Metal + Paper Package Contents: 1 set * ekg calipers 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.