Features: This adapter is provide greater flexibility and convenience for flashlight users, allowing them to utilize their existing supply of 18650 batteries without having to purchase a new 21700 battery. By simply inserting the 18650 battery into the adapter, users can enjoy the same level of performances and reliability as they would with battery. By choosing to use 18650 adapter, users can save both time and money by avoiding the need to purchase new 21700 batteries or dispose of their existing supply of 18650 batteries. This not only reduces waste and environmental impact but also provides a more cost-effective solution for those who already have a large collection of 18650 batteries. Selected from ABS with fire retardant properties, and features highly conductive copper plated battery contacts. Our battery sleeve is provide safe performances, with high-quality materials and construction that meet industry standards for fire resistance and conductivity. Specifications: Component:ABS Size:Approx.60x21.2mm/2.36x0.83inch Package Includes: 4Pcs Battery Adapter note: 1.Please allow 1-2cm errors due to manual measurement, making sure that you not mind before order. 2.Due to the differences between different monitors, the picture may not reflect the actual of the item.