The B0310J50100AHF from TTM Technologies is a Balun with Frequency 300 MHz to 1 GHz, Amplitude Balance ±2.5 to 2.8 dB, Phase Balance 34 to 36 Degree, Insertion Loss 0.8 to 1 dB, Power 2 W. Tags: Surface Mount, Unbalanced to Balanced. More details for B0310J50100AHF can be seen below.