Don't Spend $20 or even $10. Might be good for $5 to break down the tool box. First, there is nothing to hold the left and right wedges together. You throw them pop. You toast, they show up. Of the two tension springs, one popped out and hid somewhere in the store to find it in the next scoop, and then I put it back with a compliment of a bumpy ride while I shaved the edge. Blades dull upon arrival. Still, there should be a decent cut. I don't know if it's just this brand or a specific manufacturer or if they all work the same way. You form your own opinion. I ditch the tool and go the old-fashioned route, using a hand router with a trimming attachment.