Martin Yale 1628 Desktop Letter Opener with Concealed Blade, Gray, 8"x10-1/2"x4-3/4" Dimensions; Electric Operating Mode; 3000 Envelopes Per Hour; 1" Stack Capacity Automatically feeds and opens a stack of envelopes at high-speed Accepts standard-sized business envelopes Handles a stack of envelopes up to 1 Inch high Blades are fully enclosed to protect fingers Operates at a speed of up to 3000 envelopes per hour