The ML4609 from Spectrum Control is a RF PIN Diode with Forward Current 10 to 100 mA, Reverse Current 10 uA, Breakdown Voltage 15 to 25 V, Thermal Resistance 40 to 50 Degree C/W, Forward Resistance 0.8 to 1 Ohms. Tags: Surface Mount. More details for ML4609 can be seen below.