#10 Policy Envelopes Envelope Flap: Straight FlapSize: #10 (4-1/8" x 9-1/2")Closure: Peel & SealPaper Weight: 32#The #10 Open End Envelope (4 1/8" x 9 1/2") with the flap along the short side. Perfect for sending important documents or flat items, as well as small items and parts. The envelope's side flap prevents contents from falling out, and the Peel & Press adhesive strip provides for easy sealing. Available printed or plain.