The MA4L021-1056 from MACOM is a Limiter Diode with Frequency Range 10 MHz to 18 GHz, CW Input Power 3 W, Input Peak Power 49.5 dBm, Capacitance 0.4 pF, Series Resistance 2.1 Ohms. Tags: Surface Mount. More details for MA4L021-1056 can be seen below.