<!--013-->Rubber O Rings - 3mm (x 50) <!--013-->Rubber O Rings - 3mm (x 50) Rubber O Rings - 3mm (x 50) 3mm rubber o rings, pictured with a 5p £2.00 Out of stock. Pack of 50 3mm rubber O rings, to fit our 3mm rubber cord. These rubber O rings can be used for spacers, or as a neat finish to each end of a row of beads. NB: The fit of these O rings is a little loose on our 3mm cord. So will not hold the beads in place, as is case with the 2mm O rings on our 2mm cord.