Quality Park No. 10 Single Right Window Envelopes - Single Window - #10 - 4 1/8" Width x 9 1/2" Length - 24 lb - Adhesive - White - Wove - 500 / Box No. 10 Right Window Envelopes are essential for your business. 24 lb. white wove stock is perfect for professional mailings. Side seams provide a modern, clean look. 4-1/8" x 9-1/2" business envelopes feature a moisture-seal commercial flap. 1-1/8" x 4-1/2" window is positioned 4-1/8" from the left edge and 1/2" from the bottom to accommodate right-side addressing.