TCC-120I is an isolated RS-422/485 repeater designed for users who need an industrial grade interface conversion product to extend RS-422/485 transmission distance. Its superior industrial application design, which includes DIN-Rail mounting, terminal block wiring, external terminal block power, and optical isolation for system protection, makes TCC-120I suit able for use in critical industrial environments. TCC-120 (DIN-RAIL-MOUNTABLE - RS422/485 repeater - surge protection) List price: $131.00 Sale price: $112.40 TCC-120i (DIN-RAIL-MOUNTABLE - RS422/485 repeater - surge protection and optical isolation) List price: $215.00 Sale price: $184.47