80 Pieces of Square Flat Back Sew On Acrylic (plastic) Rhinestones, Size: 10mm or about 3/8 These jewels have 2 holes for sewing that are about 1mm in diamater. Large Allstarco 10mm Blue Aqua CH24 Flat Back Sew On Round Beads Self Adhesive Gems Allstarco 14x10mm Blue Aqua CH24 Flat Back Octagon Sew On Make sure to check out our store Allstarco USA, we have over 2000 of beautiful acrylic gems in different sizes and shapes, from Tiny 1., 5mm up to HUGE 60mm. Perfect for jewelry making, fabric embellishments, garments, Costume making, cosplays, clothes and shoes.