The ML4630 from Spectrum Control is a RF PIN Diode with Forward Current 10 to 100 mA, Reverse Current 10 uA, Breakdown Voltage 200 to 250 V, Thermal Resistance 15 to 20 Degree C/W, Forward Resistance 0.6 to 0.8 Ohms. Tags: Surface Mount. More details for ML4630 can be seen below.