This part is a kind of semiconductor called SRD-S-124D.
Function of this product has Relay.
Manufacturers : Sanyou
Image and pinout :
Some of the text within the PDF file :
SANYOU RELAYS Relays for advanced technology Miniature Power Relay SRD-Series Contact Capacity Features ● High contact capability： 12A switching capability. ● Low coil power consumption, low price. ● Microminiature relay, standard PCB terminal. Safety Approval UL，C-UL File No.：E190598 TUV File No.：R50142424 CQC File No.：CQC02001002126 VDE File No.: 40034479 Model Nominal switching capacity (res. load) Max. switching current Max. switching voltage Max. switching power SRD -DM 10A 277 VAC 15A 277 VAC 2,77 0VA SRD -D & SRD-DB 7A 250VAC 12A 250VAC 1,750VA Charateristic Data Contact material Initial contact resistance (at 6VDC 1A) Operate time (at nominal volt.) Release time (at nominal volt.) Initial insulation resistance Initial dielectric strength Vibration resistance [ ... ]