The HR1N3646 from Micross is a Space Qualified Diode with Forward Current 0.26 to 0.6 A, Forward Voltage 5 V, Reverse Current 1 to 20 uA, Reverse Voltage 2500 V, Repetitive Peak Reverse Voltage 2500 V. Tags: Axial-Lead. More details for HR1N3646 can be seen below.