This standard size 10 x 13 clasp envelope is made of 110 gsm brown kraft paper. Each envelope has a two-Prong metal clasp in the center of the opening ready to give extra security for closure. The Flap has a pre-punched hole in the center perfectly lined up with the two-prong metal clasp. It also has pre-applied adhesives that s dried and will be ready to stick when moisture is applied. Includes 100 envelopes.