The MSL1211 from Massachusetts Bay Technologies is a RF Schottky Diode with Peak Reverse Voltage 4 V (Breakdown Voltage), Forward continuous Current 1 to 5 mA, Forward Voltage 0.30 V, Power Dissipation 250 mW, Capacitance 0.12 pF. Tags: Chip. More details for MSL1211 can be seen below.