(30) Magazine Book Heavy Duty Divider Cards - White, 40mil - 8 1/4" x 11 3/4" - #MANS85WH40 Reusable - Simply flip over or turn upside down! Easy to label with a permanent marker or affixing a label. You can even turn them upside down & reuse! 40mil Thick 8-1/4" x 11-3/4" They're durable, and feature rounded corners to prevent jabbing yourself!