500pcs 18650 Lithium Battery Holder Hard Shell Anti Vibration Plastic Battery Pack Bracket Cylindrical Cell Batteries Stand Spacer DIY. Features: 18650 cylindrical battery holder, fire retardant pc+pp+gp materials, crack resistant edge with the slot, battery installation hole diameter 18.3mm, 1-linked structure, nickel plate vibration test can be conducted without attachment to any device. Suitable for all types of battery assembly including DIY options.