No. 8-5/8 Single Window Security Tinted Check Envelopes feature a fully gummed flap for a secure seal. Single window conveniently accommodates a printed address to eliminate handwritten addresses. Blue security tint keeps contents confidential and is perfect for sending checks through the mail or hand delivery. Side seam construction and 24 lb. bright-white stock add a modern, professional look. Send out business correspondence with the assurance of quality and security these envelopes provide.No. 8-5/8 Single Window Security Tinted Check Envelopes feature a fully gummed flap for a secure seal. Single window conveniently accommodates a printed address to eliminate handwritten addresses. Blue security tint keeps contents confidential and is perfect for sending checks through the mail or hand delivery. Side seam construction and 24 lb. bright-white stock add a modern, professional look. Send out business correspondence with the assurance of quality and security these envelopes provide.