YAJU Compact Pack: Classic style kraft paper index cards. 6 pack with pages in 6 colors (light Green, Blue, Pink, Red, Purple, Ocher). Comes with 6 binder rings for easy use. Smart Design: For easy sorting and safety use, all cards are shaped to rounded edges and feature a pre-punched hole. Comes with 6 rings for easy classification so you could easily keep them neat and organized. Each card measures 3.5 X 2.1 Premium Quality: Thick cardstock plus anti-corrosion binder ring. 6 colors mixed in a pack and bound with covers. Easy to use and durable. Study cards can be printed in a standard printer. Apply Your Own: With a marker you could easily apply words, numbers and equations on these double-sided cards, make your own demonstration and education kit. 6 colors, you can also regroup them with similar colors for certain categories. Perfect For: Home and preschool education on teaching, reviewing and practicing. Could also be used as notepad, memo.