I've been noticing that a large number of headphones have interchangeable pads. A staggering number of headphones are compatible with these Beyerdynamic velour pads. The DT250 and DT280 that they were originally designed for, the Sony MDR-V6/7506, CD700, ATH-M30/M35, M50, and Monoprice 8323 to name just a few.
Why? Is it because it is the best design for the average human ear? Just coincidence?