When stringing beads with larger holes, (2.5mm or 3/32in or larger) i.e. some big hole beads or lampwork beads, you will notice that sometimes the beads do not sit straight on the beading wire. These aligners have a dimple or inset to help keep the bead straight.
Try them also as a end cap for peyote or stitched tubes.
8mm x 3mm Hole size is approx. 1mm ID. By the pack of 10.