The Metolius Ultralight Curve Nut are 30% lighter than the competition.  The anodized heads and collars are color-coded to match.  They combines the stability of 3-point contact with the ease of a straight-sided taper nut. Side-to-side curve for greater stability in flaring placements and straight-sided taper makes it easy to judge placement quality.  These stoppers will become your go to stopper on your rack.