Slot Radio Cards in an e280r

[BrassBalls]

I'm pretty sure I know the answer to this question already, but thought I'd ask here anyway...

Can the Slot Radio cards be played on an e280r? I couldn't resist getting 3 of them off of ebay for ~$25 total thinking they might work. I've inserted all 3 in the Sansa and can't see them with any menu settings or when connected to my comp in either mode. Are my only options getting one of Sandisk's compatible players or reselling them?

TIA

[CrowdAds]