The BD1222J50200A00 from Anaren Inc is a Balun with Frequency 1.2 to 2.2 GHz, Amplitude Balance ± 0.9 dB, Phase Balance 6 Degree, Insertion Loss 0.6 dB, Power 2 W. Tags: Surface Mount, Unbalanced to Balanced. More details for BD1222J50200A00 can be seen below.