I apologies if everyone already knows this, but....
(Source)
"If by chance your FLU screen is ever damaged, I did contact the company that manufactures them for Game Park - HaHotech. They informed me that FLU kits can be purchased directly from them by existing FLU owners for $30, or you can send your GP32 FLU to them (all the way in South Korea) and they'll replace your damaged FLU for $50."
(Source)
"If by chance your FLU screen is ever damaged, I did contact the company that manufactures them for Game Park - HaHotech. They informed me that FLU kits can be purchased directly from them by existing FLU owners for $30, or you can send your GP32 FLU to them (all the way in South Korea) and they'll replace your damaged FLU for $50."