- Not a diagnostic device: this electrocardiogram ruler card is a practical reference tool for interpreting ECG results and is intended for use by medical professionals. It comes in a protective case for easy transport and safe storage. - 7-stage ruler with 7-step guide: the 7-stage ruler is an essential instrument for accurate ECG interpretation, designed to help clinicians analyze complex heart data quickly and consistently. - Wide applicability: widely used in hospitals, clinics and educational environments, it provides instructed support for ECG analysis and adds value to every medical toolkit. - Design and materials: portable acrylic ruler card with a clear ruler surface, featuring a 7-stage ruler and a 7-step guide to ensure a reliable reference in medical environments; supplied in a protective case. - How to use: when reviewing an ECG, place the card alongside the printout or display and follow the 7-stage/7-step guidance to reference key intervals and patterns during analysis or teaching. - Use scenarios: - In a hospital ward to quickly verify rhythm and interval interpretations. - In an outpatient clinic to support ECG follow-up assessments. - In classrooms or teaching labs to instruct students and residents on ECG analysis. - Specifications: material is acrylic; clear ruler surface; includes a protective case; 7-stage ruler and 7-step guide; portable and lightweight; not a diagnostic device.