On one of my Tower orders they sent the wrong size prop and a crystal I didn't order (or pay for). I called them. They told me to keep the crystal and prop and they would send the right size prop. A few days later the wrong size prop showed up again. Before I had a chance to call, another package arrived with the right prop. Fortunately, even though they were the wrong size, I can use them on another plane. As has been said, little mistakes can happen, not a big deal as long as they are easy to correct. In all, I've been very happy with Tower and continue to shop there.