The Practi-WLCRdM is a CPR feedback device designed to measure both compression rate and depth when practicing chest compressions on a manikin. The NEW Practi-WLCRdM device is worn on the student's wrist. The wristband is designed as a one size fits all and is latex free. The unit comes equipped with a 3-4 hour rechargeable lithium battery and the battery can be charged via USB port in 2-3 hours. When measuring the depth of the compressions the unit provides an audible "beep" when compression depth is not within the range of 2"-2.3". To measure the rate there is a diode that illuminates red when compressions are below 100 cpm or above 120 cpm. The diode will illuminate green when the user's compressions are between the recommended 100-1200cpm. This device was designed specifically for customers who have already invested in their CPR manikins that may or may not be fully compliant with the new 2019 AHA Guidelines. Sold at an economically affordable price, it allows its instructors to purchase multiple units. Band: 10 x 0.75 inches Protective Case: 3.5 x 1 inch Weight: 0.1125 lbs