ekg ruler vertical badge id card pocket reference guide ecg scrubs and stuff llc this card has a great diagram of a basic ekg with all the common terminology and overview of the different points on an ekg. additionally it has an ekg ruler on one side that helps you measure the heart rate. the ruler on the other side helps to determine normalcy of common distances including pr interval, qrs complex, and qt interval. <br> <br> this badge card comes from a series of cards that puts hard to memorize information at your fingertips. it has a standard slot pre-punched that will work with badge clips and badge reels. <br> <br> this card also comes in both vertical or horizontal format. purchase whichever version works best for you. <br> <br> card made of durable plastic, is waterproof, and is about half the thickness of a credit card so it wont weigh down your badge reel or feel bulky. <br> <br> double sided and uses the entire printable area to maximize the total information. same as a standard badge id card (or credit card size; 3 3/8" by 2 1/8").