McCoy EKG Ruler 6.5"x1.75" SKU: 10039354 $3.95 Ship Available Pickup in Store - FREE! Select Store to check availability. Quantity -+ Add to Cart Details 6.5” x 1.75”Clear plasticEasy to readFigure correlations for time intervals, rates & voltage from 25mm to 50 mm, and heart rate, cycle length and QT i... DetailsBackDetails6.5” x 1.75”Clear plasticEasy to readFigure correlations for time intervals, rates & voltage from 25mm to 50 mm, and heart rate, cycle length and QT intervals.See MoreSee Less Reviews 0 BackRatings & ReviewsNo reviews availableBe the first to Write a Review