Instruct: Classify the given Amazon review into positive or negative sentiment.
Query: Poor quality control

This item arrived defective (electronics did not work), and I returned it for an exchange. Amazon immediately sent out another one by overnight express delivery. Unfortunately the second unit was also defective. Since two other reviewers had similar problems, I can only conclude that the quality control for this expensive item is not very good. Even if I received a working unit, I would be afraid that the electronics wouldn't last very long. I returned the second unit and ordered a Howard Leight Impact Sport Earmuff instead.