This is SSR-10DA Single-phase Soild State Relay. It can be driver by Arduino directly without any expanding circuit because of its built-in opto-couple. The plastic protective cover makes it be a safer relay module.
SSR solid state relay uses inflaming retarding engineering plastic shell, epoxy resin encapsulation and screw terminal connection. This series solid state relay has high structural strength, impact resistance and strong resistance to vibratility. The low input drive current makes it convenient to connect with computer terminal and various digital programmable interface circuit.
It is widely used in automation control field such as petrochemical equipment, food machinery, packaging machinery, textile machinery, CNC machine, plastic machinery, fitness equipment, recreational facilities, especially suitable for severe environments like corrosion, moisture, dust prevention, explosive requirements and frequent switch occasions. SSR series solid state relay are update replacement products of a.c. contactor.