Quality Park Redi-seal 2 Window Envelopes – Double Window – #8 5/8 [3.63″ X 8.63″] – 24 Lb – Self-sealing – Wove – 500/box – White (QUA24539). Product Title Quality Park No. 8-5/8 Double Window Security Tint Envelopes with Redi-Seal® Self-Seal (QUA24539).