PB Hard Case models ending with: DKO are Divider Kit Only replacements and UP-GRADES to the foam interiors. For a more substantial solution to the foam, the DKO is used for improved performance. They include pouches, pillows and divider planks, which give you greater flexibility in configuring your ever-changing equipment requirements. DKO's can even be used with many competing brands of shipping cases with worn out foam interiors.