These days there are only a few major NAND flash manufactures. But buying really cheap, don’t be surprised you are getting some companies marginal quality product that wasn’t good enough to be sold under their own brand or a product that isn’t what it says on the label. 4GB is really low density, I’d rather spend a few more dollars buying SANDISK or Lexar from B&H. SDD storage replacement usually come with a controller to manger write / erase as high density flash cycles capability have plummeted with density increase. Can’t believe you can buy a memory for that stand alone.

The higher density FLASH ones are now all 3D and are only good for a few hundred to a few thousand erase and writes. For reads they are actually very reliable, but certainly not As durable as HDD but not as fragile.

Thus is if you write and erase often, I’d highly recommend you get new cards every few years, if all you do is store once and read probably not as big a deal.

The most reliable products are in your iPhone, Enterprise SDD, PC SDD, the your flash cards and then the thumb drives and bargain off brands bring up the bottom