1. Sound output: up to 115dB
2. Acquired sound: 28dB or more
3. Total harmonic distortion: 7% or less
4. Frequency range: 300-4800MHz
5. Input noise: within 29dB
6. Voltage: DC 1.4 V
7. Voltage: within 1.2mA
8. Power supply: 1 AAA battery (not included)
9. Weight: about 108g
10. Size: about 5.9 x 3.7cm

Features:
1. Multi-step adjustable
2. Dry battery power supply (not included), more convenient
3. Medical grade silicone earplugs, comfortable to wear
4. Small body, light weight, not easy to wear and tear, no pressure, easy to carry
5. Can be clipped on the collar and pocket

Packing list:
- Main unit x 1
- Earphone cable x 1
- Earbuds x 4
- Instruction manual x 1