The BCW Pro 2-Pocket 4x10 Envelope page is an acid free archival quality product that is perfect for storing First Day Covers and Envelopes and can be used in the office or for stamp collecting. This product features high-clarity polypropylene and top loading pockets with strong welds. BCW Pro 2-Pocket Envelope pages fit all standard 3-ring binders and albums. Use the 2-pocket page to protect, store, and display your collectible covers and envelopes.