Summary: The Sony MDR-AS20J Active Headphones are a suitable choice for MP3 player owners who simply want a more secure pair of earphones for the gym, but don't need better audio quality than that of stock earbuds.
Pros: The Sony MDR-AS20J earphones are inexpensive, uniquely designed, and offer an understated style. A detachable clip keeps the cable out of the way during activity.
Cons: The Sony MDR-AS20J ear loops are not adjustable and some users will not be able to achieve a secure fit. Package doesn't include a case or any extras. Some music sounds muffled.