The 5400BL15K050 from Johanson Technology is a Balun with Frequency 4.9 to 5.875 GHz, Amplitude Balance 2.0 dB, Phase Balance 10 Degree, Insertion Loss 1.2 dB, Power 3 W. Tags: Ceramic, Surface Mount, Unbalanced to Balanced. More details for 5400BL15K050 can be seen below.