Martin Yale 62001 High-Speed Letter Opener has a variety of features that make it a great fit in large offices as well as mailrooms. Great at processing a large volume of mail quickly, the Martin Yale 62001 letter opener can open up to 17,500 envelopes every hour. That's a lot of opened envelopes in a short amount time! Capable of opening envelopes as much as 1/4" thick, the automatic opener can process a tall pile of envelopes up to 6" high. The adjustable width settings allow the user to accommodate envelopes of different shapes and sizes as well.