Instruct: Classify Amazon reviews into positive or negative sentiment
Query: Expensive, but does EXACTLY what it says.

Great adapter. If you print a lot of envelopes at once(we do a lot of mail-merges, this is a great addition to your 4250/4350 printer.Actually very heavy unit. Attaches to the front (remove that little plastic cover strip) above Tray 1, and has its own locking attachment arm, power connector, and its own feeder/rollers. The middle (the flat piece in the center) is a locking up/floating down weight to ensure the envelopes feed well.Believe it or not, it actually prints envelopes about twice as fast as using the built-in tray 1, and is about 1/2 as loud too. The feeder unit on this is much quieter than the pickups on tray one, which makes sense since this is completely dedicated.Very well designed unit, and very helpful for envelope printing. 4 out of 5 stars, simply becuase its SO much money for what it does. $200+ for the attachement is a little outrageous. Still not sorry I bought it.