... most professional manufacture in Asia Mining telephone,dust proof telephone KNSP-08L Applications: As Public telephone for indoor or outdoor, Taxi or bus ... aluminium alloy die-cast body, Vandal resistant and tamper-resistant hardware, simple installation.2. Full keypad with memory, 10 button programmable ... RLR<-1,STMR>10, output impedance is 600 Ohm. Mining telephone, dust proof telephone KNSP-08L