The Tek Grip knob is a style of control knob used on several models of Ibanez guitars.
It is a round, machined metal knob with medium course diamond knurling on the sides and a domed flat, polished top. It fits a 6mm fine spline, split shaft potentiometer. A small retention screw on the side ensures a solid fit.
The Gotoh VK1-19 is a similar knob used on high-end models.