Top-loading, super durable polypropylene security envelope offers a safe way to store computer disks, CDs, photos, evidence files, x-rays and a variety of other documents. Waterproof and tear-resistant envelope is secured on all four sides, reducing the potential for lost documents or articles. The string-tie closure makes access easy. Security envelope fits both folders with two-hole fasteners and three-ring binders. Side-loading for fastener folders and top-loading for three-ring binders. Attach security envelopes to your folder or secure into your binder through the four-hole punched flap on the envelope.