The FMBL1004 from Fairview Microwave is a Balun with Frequency 100 to 520 MHz, Amplitude Balance ±0.4 dB, Phase Balance ±5 Degree, Phase_Shift 180 Degree (Difference), Insertion Loss 0.3 dB. Tags: Surface Mount, Unbalanced to Balanced. More details for FMBL1004 can be seen below.