Quality Park Inter-Department Envelopes, String-and-Button, White, 10 x 13, 100 per Box, (63663) ANTI-MICROBIAL: Treated with an antimicrobial agent to guard against the growth of bacteria, mold, mildew, fungus, and odors SECURITY TINTED: Have ease of mind that your contents are secure with the security tinting 52 ENTRIES: Printed on both sides with space for 52 entries STRING-AND-BUTTON: Convenient when reusing the envelope, easy to open and close repeatedly FEATURES: 100 White, 10 x 13, inter-department envelopes