The 20000mAh DIY power bank case kit for 21700 batteries is designed for customized portable power bank projects. WIN WIN provides plastic injection molding and OEM customization based on customer drawings and design requirements. Choose from ABS, PP, PS, PE, PVC, PA6, HDPE, and other suitable plastics, subject to project evaluation. Contact us to discuss enclosure dimensions, surface finishes, and tooling requirements for your project.