These are original, genuine, SA Ice Cap keycaps from Signature Plastics.
These have been discontinued and replaced with the similar (but not the same!) "SA-P Snow Cap" keycaps by Signature Plastics.

These keycaps are not sculpted / profiled unlike most SA keycaps. All keys are size R3. The keyboard has a flat uniform look and feel to it. Kind of like... a tray of ice!

The keycaps fit TKL (Ten Key Less) boards and smaller such as 65%, 60%, 40%, OLKB Plancks etc.

I'm selling as I have too many keyboards and need to cut down on my situation a bit.