Three stages of protection on every data line 2.Protected signal ground connection 3.RS-422, RS-485 versions Easy to install IEEE 1000-4-5 and ITU-TK20&K21 are the recognized standards for top quality surge protectors, FL485 have high respond speed, low output rudimental voltage, ascendance transfer performance . All have #10 ground screws which must be connected to a solid ground. Features1. ...