Please be aware that these glow-in-the-dark beads are made overseas, and while there are a limited number, some may have imperfections. I guarantee they will glow. As shown in the third photo, this is the glow after absorbing light from a headlight for about 5 minutes. - Quantity: 150 pieces - Diameter: Approximately 4.8mm - Through-hole: Approximately 1.6mm