The Z7550-FMSF+ from Mini Circuits is a Balun with Frequency DC to 2.3 GHz, Insertion Loss 0.02 to 0.43 dB, VSWR 50 omhs: 1.11:1 to 1.50:1, 75 ?: 1.08:1 to 1.48:1. Tags: Module with Connectors, Unbalanced to Unbalanced. More details for Z7550-FMSF+ can be seen below.