The BD1722J50100AHF from Anaren Inc is a Balun with Frequency 1.7 to 2.2 GHz, Amplitude Balance ± 1.2 dB, Phase Balance 6 Degree, Insertion Loss 1.2 dB, Power 2 W. Tags: Surface Mount, Unbalanced to Balanced. More details for BD1722J50100AHF can be seen below.