Instruct: Classify a given Amazon review as either positive or negative.
Query: Overrated and Un-returnable

After reading the reviews, I purchased on these units and the sound is awful. The product description reads: "The CX 300 are high-quality stereo ear-canal headphones with powerful, bass-driven stereo sound for listening 'on the move'...." Far from it. There is abosolutely no bass on the earbuds I received.Also, heed this warning: if you purchase this, you cannot return it. Earbuds are not returnable.