The HR1N3957 from Micross is a Space Qualified Diode with Dynamic Resistance 38 Degree C/W (Thermal), Forward Current 0.3 to 1 A, Forward Voltage 1.1 V, Reverse Current 0.5 uA, Reverse Voltage 1000 V. Tags: Axial-Lead. More details for HR1N3957 can be seen below.