Instruct: Classify Amazon reviews into positive or negative sentiment
Query: Poor manufactuing and phone call quality

I returned mine within minutes of opening them. The quality of the manufacturing was terrible. The buttons (volume and call) would stay depressed when you pushed them. They didn't click back up as they should. The headphones paired easily enough and the stereo sound quality was pretty good (not really loud enough to suit me though). However, when I made a call, the person said that they could barely hear me.Here are the cons in a nutshell:1. Poor manufacturing quality - buttons stick when pressed2. Terrible microphone quality for handsfree3. Poor battery life (4 hrs)4. Can't navigate songs (forward or back) using headset.If you want a cheap bluetooth headset, the logitech ones are awesome. They made a set that breaks pretty easily, but you can repair it with some superglue and nylon ribbon. They don't have a handsfree feature though.