Looks like Stenopus earlei, Earl's Coral Shrimp/the Two-Stripe Coral Shrimp. They're a cleaner shrimp that likes caves, crevices, and ledges, and they're reportedly reef-safe.
Edit: Just to add, they're pretty rare and quite pricy when available in the hobby (I've seen them offered for $100 and $160, and only in Australia).