500 Mixed Color Bingo Cards are durable enough for repeated use. There are 100 books per set and each book has 5 different colored bingo cards. 500 unique sheets in total. Measures 8" x12" is portable. Each one is 6 on bingo card. Printed bold numbers is easy to read for all ages. Each cards will not be duplicated. Provides you with a professional gaming experience. Made of professional grade bingo paper and they are disposible if marked with an ink marker. However, if used with bingo chips which are resuable.