Standard size #10 white color envelopes, features blue security print inside the envelope. Each envelope has pre-applied adhesives on the reams of the closure. When you are ready to mail the envelope, just peel the strip off from the adhesives and press firm to seal the envelope. Includes 500 envelopes.Details:WhiteEnvelope Size #104.125" x 9.5" (10.4cm x 24.1cm)500 envelopesSecurity Prints inside the envelope to keep people from peeking inside for important informationSelf-Seal for easy closure