The TT4-1+ from Mini Circuits is a Balun with Frequency 0.05 to 200 MHz, Insertion Loss 0.36 to 2.88 dB, Current 30 mA, Power 0.25 W, Return Loss 1.46 to 19.03 dB. Tags: Surface Mount, Unbalanced to Balanced. More details for TT4-1+ can be seen below.