We offer these unique mailers call Snap Pacs, Snap Packs, or Pressure Seal Mailers. They are unique because they are a single continuous mailer that folds and has 2 perforated edges that tear off. They are inexpensive because there is no need for an envelope. Snap Pack Mailers are easy to produce so turn times are quick! Pressure seal mailers (Snap Pack Mailers) are very popular and demand the attention of the recipient because often times they have a "Final Notice" letter or "Important Message".