Martin Yale 1632 Automatic Letter Opener, Automatically feeds and opens a stack of envelopes, Grey (PRE1632) Operates at a speed of up to 7,000 envelopes per hour Accepts a 1 3/4 Inches tall stack of envelopes The blades are fully enclosed to protect fingers Comes with catch tray that folds for easy storage A truly innovative machine, the 1632 does a continual feed of up to a 1 3/4" tall stack placed in the feed tray. Automatically feeds, opens and collects a 1 3/4" tall stack of standard size business envelopes up to 7,000 per hour. Hands-free operation, just put envelopes in position and turn machine on. Blades are fully enclosed to protect fingers. Nonskid feet. Unit operates at a speed of up to 7,000 envelopes per hour with a momentary power switch. Ideal for small to mid-size businesses