EKG ECG Nurse or Doctor Caliper for Measuring Electrocardiographs (black) High quality EKG ECG caliper for measuring electrocardiographs with precision. The circular dented arms make opening, adjusting, and grasping the arms smooth and easy. The protective caliper sleeve serves as a useful tool for measuring a 6 second strip or 12 lead EKG. Small screws make the end points long or short or the arms tight or loose for a comfortable feel. The sleeve includes a useful clip making it easy to attach to your uniform or inside your pocket.