Crafted from PVC materials, this ruler features clear, wear resistant marking for long terms use and easy portability Perfect for use in hospitals, clinics, and educational occasion where heart rate examinations and research is conducted Enhances your diagnostic capabilities with this essential heart rate measurement tool, a must having for any medicals professional Great for doctors, nurses, and medicals students who require precise heart rate analysis tool Ensures accurate heart rate measurements with our heart rate ruler, designs to assist medicals professional in analyzing heart health, Manufacturer: Kelisdi