This part is a kind of semiconductor called LKS1aF-18V.

Function of this product has power relays.

Manufacturers : Panasonic

Image and pinout :

Some of the text within the PDF file :

250 mW SLIM POWER RELAY VDE LK-S LK-S RELAYS 24.0 .945 11.0 .433 25.0 .984 mm inch FEATURES 1. High sensitivity: 250mW The power-saving relay is highly sensitive at the nominal operating power of 250 mW (530 mW power consumption on LK relays). 2. High insulation resistance between contact and coil 1) Creepage distance and clearances between contact and coil: Min. 6 mm .236 inch (In compliance with IEC65) 2) Surge withstand voltage between contact and coil: 10,000 V or more 3. High noise immunity realized by the card separation structure between contact and coil 4. Popular terminal pitch in AV equipment field 5. Space-saving slim type Base area: Width 11  Length 24 mm Width .433  Length .945 inch 6. Conforms to the various safety standards UL/CSA, VDE, TÜV and SEMKO SEV approve [ ... ]

LKS1aF-18V PDF Datasheet Download