The safety feature once the lid is secured is of poor design. There is a lever in the handle that activates a switch at the bottom of the handle which interacts with a similar probe on the base of the unit. Since it is made of some sort of soft material, only a few uses seemed to cause 'erosion' of the tips of the safety device that made the unit inoperable. The plastic tips should have been made of more substantial material such as stainless steel. The blade also did not have a sharp edge and trying to shred vegetables (Cranberries) was less than satisfactory.
This small chopper was bought as refurbished, but when it arrived, it lookes as brand new. Worked just fine and all the pieces were there, including a mfgs, warranty. Overstock.com's low cost of shipping and great services sealed the deal for me!