Features: Enhances your ECGs interpretation skills with our ECGs 7 Step Ruler, designs for precise and quick measurements to aid Medicine Professional in improving diagnostic efficiency. Produced from ABS material, this ECGs ruler is easy to clean and comes with a protective sheath for convenient portability and storage. Suitable for doctors, nurses, and Medicine students who require accurate ECGs analysis tool in their practice. Perfectly suited for use in hospitals, clinics, and educational setting, supporting routine ECGs assessments and training environment . This portable pocket ECGs card ruler serves as essential reference guide, ensuring you have reliable ECGs assessment tool at your fingertips. Specifications: Material: ABS Size: about 8.7x5.5cm/3.43x2.2inch Package Includes: 1xECG Ruler with 1 Storage Box Or 2xECG Ruler with 2 Storage Box note: Please allow 1 to 3cm error due to manual measurement, please make sure you do not mind before you bid, Due to the differences between different monitors, the picture may not reflect the actual colorful of the item.