Sandisk 4GB MicroSDHC 4GB MicroSDHC memory card - memory cards (MicroSDHC, -25-85 °C, Black, SD)

What class is this 4gb micro SD card?

does it work on Samsung s390g?

What is the transfer speed class

I put microsd card in the adapter, laptop won't detect it. tried it 2 other computers, no luck. idk if i did something wrong or if its faulty. advice?