The Inviz Wire Pro spinnerbait is built around a frame constructed from .040" gauge heat-treated, brown color super wire that is stronger than traditional stainless wire. And is much less visible to the fish. The "wobble" head design eliminates torque on the wire while producing unbelievable vibration. This design creates very straight tracking. Even at higher retrieve speeds and prevents fish from gaining any leverage to throw the bait. The sliding sleeve feature allows you to fully customize your spinnerbait. By changing out head size or head/skirt color as well as blade size/color in seconds. Smart mouth plus heads for the night thumper version are available in black, Hook Size: #4/0