Comparison : Item # N1 .312" Press-On Knurled Knob,
Item # N2 .375" Press-On Knurled Knob,
Item # N3 .50" Press-On Knurled Knob,
Item # N4 .625" Press-On Knurled Knob,
Item # N5 .75" Press-On Knurled Knob,