The Efest 26650 battery case holds two 26650 batteries and is molded plastic. We highly recommend using battery cases for your mod batteries as a safety precaution. Batteries should never be mishandled, improperly stored, or carried loosely in bags, pockets, purses, etc. Do not let positive and negative battery terminals connect via loose change or other conductive materials. This case was designed to provide an additional level of precaution when transporting your batteries.