Brand new Elite Medical Instruments Basix Economy EKG Calipers AND EKG Ruler combination set (EKR-203) for sale. EKG ECG Calipers to measure electrocardiogram wave sections. These EKG Calipers are High Quality and provide accurate electrocardiogram wave tracing. Made with steel and includes plastic protective cover for easy reference. Comes with reusable pvc pouch carrying case. Brand new Elite Medical Instruments EKG Ruler displays the following information: Seconds scale for PR, QRS, Cycle, Length, Coupling, Escape, and Parasystolic Intervals.