This 30cm2 box can hold up to 6 devices. It is designed to block and absorb electromagnetic radiation and radio frequency. Imbedded within its walls is a copper and aluminium alloy which has radiation blocking and absorbing properties. In back you will find multiple holes that are used to insert charging cords through, and little slits above each hole to adjust to sizes of different chargers. At the very botton you will find a little compartment which is used to store the charging port. I have used bamboo as it is more sustainable.