These Quality Park 9x12 clasp envelopes are made of extra heavy-duty 32 lb kraft for tough jobs; with clasp & gummed closures to file or ship; 100/bx Our yellow 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 Extra heavy-duty 32 lb kraft manila envelopes are designed to give contents extra protection during mailing, storage and handling A great value; large envelopes are an economical way to send manuscripts, certificates or other documents you’d rather mail flat