No. 10-1/2 envelopes with Redi-Seal feature are designed for use with Insurance Form CMS-1500 and similar forms. Redi-Seal closure requires no moisture to seal. Simply raise the lower flap and press to seal. The 1" x 4-1/2" window is positioned 4-1/4" from the left and 19/16" from the bottom of the envelope. Inside security tint offers more privacy. 24 lb.