Display: Large LCD with blue backlight (45 mm × 25 mm). Heart Rate Range: 50 BPM – 240 BPM. Modes: * Mode 1: Real-time FHR (displays current heart rate). Mode 2: Averaged FHR (smoother, more stable reading). Mode 3: Manual (user-controlled counting). Probe: Interchangeable 2MHz or 3MHz water-resistant probe. Audio: Built-in high-quality speaker + 3.5mm headphone jack. Power: 2 × AA 1.5V batteries (approx. 10 hours of continuous use). Auto-Shutoff: Powers down after 1 minute of no signal to save battery.