We took those fumbly old stacks of index cards and gave them an instant upgrade. Keep your cards organized with this 4 pack of durable and transparent snap-closure carrying cases. And that's not all. Inside each pack are 100 3" x 5" college-ruled index cards and five color dividers with customizable tab stickers for easy organization in each one. But the studying part? That's all up to you. YOU BUY, YOOBI GIVES - For every Yoobi item you purchase, a Yoobi item will be donated to a classroom in need, right here in the U.S.