WCR's (Wagner Custom Rewinds') latest pickup design is the HERC set, which takes their name from Michael Calhoun (aka the HERC) from the Axe House, who helped with the design of these new passive humbuckers. The two humbuckers in the HERC set are designed to be used primarily with contemporary high-gain amps with the mid-scoop/pronounced bottom end, but will work with all other types as well. They are completely passive, and no batteries are required.