Automatically feeds, opens and collects a 3" tall stack of envelopes at a rate of up to 12,000 per hour. Hands-free operation opens envelopes up to 1/4" thick and collects envelopes in a large catch tray. Blades are fully enclosed to protect fingers. Nonskid feet. Ideal for large businesses and mailrooms. Catch tray folds and stores attached to back of machine. Blade Type: Concealed; Blade Material: Steel.