Still VLF. Pulse induction (PI) is another entirely different method of detector. PIs are good for gold (Minelabs) or salt beaches. PIs are the BEST type for salt beaches. Also good for gold because they ignore the biggest problems it the gold areas HOT ROCKS! Going for very, very tiny gold is best done with a GMT or GB2. Minelabs good for bigger gold. I'm on someone else's computer so must keep it short. Tnx. Terry