These are Blu-Ray DVD divider cards! Our divider cards are professional heavy duty store grade divider cards. They are professional, heavy duty store grade divider cards - made out of 100% virgin high impact polystyrene (HIP). They are strong stuff - used by music stores all over the country! These cards are rectangles with rounded corners (it eliminates jabbing yourself on the sharp corners!) Superior to the "tab" style dividers because those are more likely to snap off.