Material: Zinc Alloy Package including: 50Pcs (Pack) Product weight:（15mm/7g），（20mm/9g），（25mm/11g），(30mm/13g),(35mm/15g),(40mm/17g) Those pictures are just for reference only, please check the above detailed measurement to choose the correct size, and allow 1-2mm differences due to manual measurement, thanks. Item color displayed in photos may be showing slightly different on your computer monitor since monitors are not calibrated same.