Ping P2640 Individual Open Plastic Electric Guitar Part Individual Open Plastic Polised nickel-plated construction of these ping machines includes a double-drilled shaft for vertical (solid headpiece) or horizontal (slotted headpiece) mounting. each individual machine includes open gear construction with plastic oblong button. Model: P2640 Individual Open Plastic. Polised nickel-plated construction of these ping machines includes a double-drilled shaft for vertical.