They're called "SYRYN Swimbuds Flip and Waterproof MP3 Player". Just got them a few years ago as a quick, inexpensive Amazon purchase. Looks like they're a bit more expensive nowadays, but not too bad.
They work fine-- only ones I've ever had, so I have nothing to compare them to. I can confirm they've survived over 200 hours of lap swim, though.
They work fine-- only ones I've ever had, so I have nothing to compare them to. I can confirm they've survived over 200 hours of lap swim, though.