Nakpunar 100 pcs Crystal Clear Iridescent Sew On Rhinestone - 3/8" Sew-on acrylic rhinestones have small holes, either in the middle or along the outside edge, which make it possible to attach them by sewing. Approximately 9 mm (3/8") in dimater Available more than 20 colors and 5 different design Flatback rhinestones can be adhered to surfaces by glue if you'd like to. The color may be slightly different due to screen settings.