Quality Park 9 1/2x12 1/2 clasp envelopes are a staple of every office; a gummed flap & reusable clasp make them ideal for mailing & storage; 100/box Envelopes have durable 2 prong metal clasps and reinforced eyelets to let you access your files as needed; open, close, repeat A deeply gummed envelope flap is laid thick with moisture-activated adhesive; creates a firm seal you can trust in the mail Heavyweight 28 lb kraft paper envelopes are opaque to protect private contents; strong enough for bulk mailing or organizing the office A great value; large envelopes are an economical way to send manuscripts, certificates or other documents you’d rather mail flat