1. Our bird watching recording tool uses a 8x21 focusing telescope optical glass lens, Field of View: 7.5°, effective observation distance is 5meters/5.5yd to unlimitedness, Resolution: 10 to 11in High Definition, voice ensitivity: -60 to -50dB.
2. Clear Sound Quality: Bird watching instruments headphone waveform distortion is less than 0.6%, the sound quality is clear and well restored. Directional Listening Distance: Field Quiet Environment 200meters/218.7yd, Eliminating Environmental Noise Processing.