The 2SK3515, 2SK-3515, K3515, 3515 is a 450V, 10A, 48W TO-220NIS Package MOSFET, The FUJI Electric manufacturer is a IC Chips with N CHANNEL SILICON POWER MOSFET for more details of 2SK3515 can be seen below.
The IRF9Z34 is a 60V 18A Third generation power MOSFETs from Vishay provide the designer with the best combination of fast switching, ruggedized device design, low on-resistance and cost-effectiveness.