The Z7550-FFSF+ from Mini Circuits is a Balun with Frequency DC to 2.5 GHz, Insertion Loss 0.01 to 0.42 dB, VSWR 50 omhs: 1.09:1 to 1.50:1, 75 ?: 1.09:1 to 1.50:1. Tags: Module with Connectors, Unbalanced to Unbalanced. More details for Z7550-FFSF+ can be seen below.