Swarovski bicone crystals have been upgraded to a new XILION crystal bead. The old Swarovski product code of 5301 is now 5328 and they are now known as XILION beads.
The difference in the new design? The new Xilion cut bead has more facets increasing the familiar 16 facets on the bi-cone to 24 facets so are much more sparkly! They are also slightly rounder at the centre so are more comfortable to wear. Swarovski's XILION crystal beads can be used in conjunction with their old bicone crystal beads as their shape and size remain the same, however we would not recommend using them in the same bead weaving patterns. The hole in the new Xilion cut bead is smoother which means your thread will have less chance of breaking.