The BD1722J50200AHF from Anaren Inc is a Balun with Frequency 1.7 to 2.2 GHz, Amplitude Balance ± 0.9 dB, Phase Balance 8 Degree, Insertion Loss 0.7 dB, Power 2 W. Tags: Surface Mount, Unbalanced to Balanced. More details for BD1722J50200AHF can be seen below.