Black spoke nipples also come in the "Prolock" variety.  They contain a special locking compound which sets into place once the wheel is built and prevents the spoke from loosening.  The wheel can still be trued if necessary.  Prolock are not recommended for use with Revolution spokes as the spokes tend to twist when truing them due to the locking compound, thicker spokes can resist this.

All spoke nipples sold in packs of 100, except silver aluminium in packs of 72. All are 12mm length.