For large volume, high-speed processing. Automatically feeds and opens envelopes up to 1/4″ thick. Opener accepts up to a 6″ high stack of envelopes. Feeds, opens and stacks up to 17,500 envelopes per hour. Fully enclosed, self-sharpening blade adjusts for narrow or wide cut. Removable receiving tray. AC Operation. Blade Type: Concealed; Blade Material: Steel; Length: 10.63″; Height: 12.63″.