EKG caliper measuring tool set: includes 2 EKG calipers with scale coating and 2 transparent ECG rulers for measuring ECG waveforms. The EKG caliper pen features a clip for easy attachment to nursing uniforms. Adjustable and convenient: designed for pocket carry. Needle tips are secured with screws, allowing adjustment of needle length. The joint is fixed with external screws for easy tightening adjustment. Portable: suitable for quick basic ECG measurements on paper tracings and patient monitor screens. Ideal for routine and emergency use. Lightweight and compact design. Reliable and reusable: transparent ECG rulers are made of durable plastic with protective sleeves for extended use. ECG caliper legs are wear-resistant and built for long-term reliability. Thoughtful gift: practical and useful tool for nurses and nursing students. Note: slight color variations may occur due to lighting and screen differences; this does not affect functionality. Material: Metal + Plastic Color: Black + Pink Package Contents: 2 x ECG Calipers 2 x Heart Rate Rulers Note: Light reflection and different displays may cause the color of the item in the picture to vary slightly from the actual product. Measurement error allowance: +/- 1-3 cm.