Extremely durable and can withstand repeated drops of 5 feet or more. Extra large backlit LCD is easy to read in virtually any light. Splash-resistant housing for use in harsh environments. Swivel cuff clip allows the manometer to be re-positioned for easy viewing. Auto-off function and dual low battery warnings. Recalibration reminder after 10,000 cycles (recalibration is free for the life of the instrument). Deflation rate display promotes proper technique in accordance with AHA guidelines. Pulse rate display at completion of measurement. Uses 2 "AAA" batteries (included). Latex-free.