Quality Park Redi-seal 2 Window Envelopes – Double Window – #9 [8.88″ X 3.88″] – 24 Lb – Self-sealing – Wove – 500/box – White (QUA24529). Product Title Quality Park No. 9 Double Window Security Tint Envelopes with Redi-Seal® Self-Seal (QUA24529).