The Fisher Impulse AQ Ltd is a new pulse induction (PI) metal detector that saw limited release beginning in June 2020. Production is to be limited to 99 units, with about 30 made by December 2020. The Fisher Impulse AQ is the first of a planned series of new pulse induction detectors from Fisher Research. The AQ (AQua) is a waterproof model intended for beach and water hunting. Pulse induction technology offers extreme performance on highly mineralized beaches that inhibit the depths attainable