Package & Size:Package include 3pcs EKG calipers measuring tool, meets your measurement needs; EKG Calipers Length: 11.5cm/4.5inches (from top to points).Professional EKG Caliper: Measuring tool made with high brass materials for measuring electrocardiogram wave sections.Easy to Clip: Protective cover with a plastic clip that is easy to attach to a nursing uniform; Lightweight and durable, easy to carry around. Measurement: Protective plastic cover includes a ruler for easy measurement reference.Adjustable Length:End points are adjustable to the length for you . Super and stay steady.Colour: black + blue + pinkMaterial: brassPackage Contents:3 * EKG calipers(one each in blue, black and pink)Only the above package content, other are not included.Note: Light and different displays may cause the color of the item in the a little different from the real thing. The measurement allowed error is +/- 1-3cm.