Pb fastener soft touch black 16mm amp 19mm knobs for 6mm splined shafts pb fastener 303tpn 130006 this blackgrey soft touch knob 19mm from pb fastener amp components has been manufactured with a polypropylene and thermoplastic rubber matt material on the knob making it soft and very comfortable to handle the splined 6mm spindle socket guarantees a secure grip even on smooth spindles the combination of this particular knob features a black body and cap with light grey pointer pb