Quality Park #8-5/8 Double Window Security Tinted Check Envelopes with a Self Seal Closure, 24 lb White Wove, 3-5/8 x 8-5/8. 500 per Box (24539) CONVENIENT DOUBLE WINDOW: Display the sender and receiver addresses through the double window openings. Compatible with most standard 3-1/2" x 8-1/2" checks for payroll and accounts payable applications, this double window envelope not only saves time but also makes sure the check is delivered straight into the customer's hands!The 7/8" x 3-1/2" top window is positioned 5/8" from the left and 2-1/4" from the bottom. The 1" x 4" bottom window is positioned 5/8" from the left and 5/8" from the bottom. ENHANCED PRIVACY FEATURES: Protect sensitive client information with these security tinted envelopes. The reflex blue pattern lining the envelope's interior makes it impossible to see the details of the contents, even when held up to the light. Mail checks, statements and other important documents with confidence. REDI-SEAL SELF ADHESIVE CLOSURE: With the Redi-Seal closure, envelopes do not require moisture to seal. The unique double-flap design keeps the gum from sticking before use. Simply raise the lower flap and press to seal. 500 ENVELOPES IN EACH BOX: ideal for both everyday office use and bulk mailings, each box of Quality Park #8-5/8 Double Window Security Tinted Check Envelopes provides a long lasting supply!