A balun is a type of electrical transformer that can convert electrical signals that are balanced to signals that are unbalanced and vice versa. They are also used to change impedance of twisted pair's 120 ohm to coaxial's 75 ohm. An E1 balun's function is generally to convert an E1 carrier signal from coaxial cable to UTP CAT-5 cable.
Balun-B2/S, Two female BNC box type
RJ45 Shielded to 2xBNC Female
RJ45 PIN ASSIGNMENT: P1(+) / P2(-), P4(+) / P5(-), $7.50 each