RED Official NGC Storage Slab Holder Box - Used - Can hold 20 NGC Slabs! The RED Official NGC Storage Slab Holder Box is a used product that can hold up to 20 NGC slabs. It is designed specifically for storing certified coins with the NGC certification. This holder box provides a secure and organized way to keep your valuable coins protected while also allowing for easy access and display. With its sturdy construction and dimension of 12" x 8" x 4", it is a convenient and practical solution for any coin collector looking to properly store their NGC certified coins.