500ct #10 Double Window Envelopes - Gummed Seal, Security Tinted Envelopes.("9 1/2" X "4 1/8") 500 Count: #10 Double Windows Envelopes, White, Security Tinted For Letters, Invoices and Statement Gummed Seal - Just moisten or lick the flap and fold it over to create a strong lasting seal 9 1/2 X 4 1/8