Instruct: Classify a given review as either positive or negative.
Query: Best headphone for under $50

The Sennheiser PX100 is a small, lightweight headphone. It delivers amazingly crisp, punchy sound with a strong bass response even when used with Mp3, iPod, DiscMan or other portable player device. It is also good looking, durable, and has the ability to fold up tiny like a pair of sunglasses. I will recommend this headphone to anyone who want to upgrade your headphones for your portable player or iPhone.