This relay module is 5V active low. It is a single channel relay interface board, which can be controlled directly by a wide range of microcontrollers such as Arduino, AVR, PIC, ARM, PLC, etc.
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.
The HM628128A is a CMOS static RAM organized 128 kword * 8 bit. It realizes higher density, higher performance and low power consumption by employing 0.8 µm Hi-CMOS process technology.