take the description from here
http://www.koss.com/en/products/headphones/on-ear-headphones/ED1TC__ED1TC_Insitutional_Headphones
- Earpiece design - Over-the-head
- Earpiece type - Binaural
- Minimum frequency response - 100 Hz
- Maximum frequency response - 20 kHz
- Connectivity technology - wired.Sensitivity: 98 dB
- Earpiece design - Over-the-head
- Earpiece type - Binaural
- Minimum frequency response - 100 Hz
- Maximum frequency response - 20 kHz
- Connectivity technology - wired.Sensitivity: 98 dB