The ESL0510A2 from Eclipse MDI is a Limiter with Frequency 0.5 to 1.0 GHz, CW Flat Leakage 18 dBm, CW Flat Leakage 0.06 W, Peak Flat Leakage 20 dBm, Peak Flat Leakage 0.1 W. Tags: Module with Connectors, PIN-Schottky Diode. More details for ESL0510A2 can be seen below.