The specifications on the package say it works with SD cards up to 2GB but I've used 4, 8, 16, 32GB cards with it.

Today I got a 64GB SanDisk card, plugged it into the player, connected USB and there it was in Explorer. Copied some tracks over, disconnected and, nope, doesn't read the card. :(

Then I checked the card format, exFAT. The others were all FAT16 or FAT32! A bit og a Google found Ridgecrop Consultants Ltd. free FAT32 formatter utility. I downloaded and used that to reformat it then copied some tracks over.

IT WORKS! Somehow this player made before the SDHC and SDXC standards existed is compatible with those cards (both as a generic reader and playing audio from them), as long as they're FAT32 format. I wouldn't be at all surprised if it can go even bigger.

Mine does have a label on the back SUFFIX NO.:B1 I don't know if that has anything to do with its way beyond original specification ability.