The EKG ruler features: Seconds scale for PR, QRS, Cycle, Length, Coupling, Escape, and Parasystolic Intervals Measures just 1 11/16" x 6 3/8" small enough to fit in a medical coat pocket

Complete with protective sleeve

The EKG Caliper features:

• Hardened steel arms and points for accurate measurement of tracing intervals
• Point protector has built-in 40mm metric scale Measure 4 3/4"