Bead diameter and hole sizes. 2.5mm - 1.2mm hole 3mm - 1.2mm hole 4mm - 1.5mm hole 6mm - 1.8mm hole 8mm - 2mm hole 4mm x 3mm - 1.3mm hole 7mm x 4mm - 1.5mm hole 4mm roundelle - 1.5mm hole. Please visit our other listings for more fantastic offers, findings and beautiful jewellery. Feel free to get in touch with any questions.