About 4”. Been with me for a week, eats well and no illness that i can see. Bought from FNM but adding corals now. FNM told me it doesn’t eat corals. RFG: saw it nibble on my zoas once so unlikely to be reef safe. Did not touch my snails though. Good for FOWLR. Collection in east. Pm me, thanks! Sent from Singapore Reef Club mobile app