10 Regular Business Envelopes with Left Window, Security Tinted, Gum Flap, Premium 24lb White Paper, 500/box (GF10LWT) Standard No. 10 ( 4 1/8 X 9 1/2) with Left Window 500 Envelopes per Box Standard (1-1/8" x 4-1/2" Window) positioned 7/8" from left and 1/2" from bottom Gummed Flap 24lb White Paper