China 2017 New Prison Telephone, Inmate Internet Telephone, Jail SIP Telephone, LCD Optional, Find details about China Prison Telephone, SIP Phone from 2017 New Prison Telephone, Inmate Internet Telephone, Jail SIP Telephone, LCD Optional
Operating Temperature | -30°C to +65°C |
Storing Temperature | -40°C to +75°C |
Ringing Tone | Shrill warble tone 80 dBA @ 1 metre typical |
M.T.B.F. | in excess of 50,000 hours using |
MF (tone) | MF (tone) |
Lightning /Transients | Protection to ITU-T k.21 enhanced levels |