What is the difference between these two sony earphones?

[Mysteriouskk]

What is the difference between this one MDR-EX71SL/WK

and this one MDR-EX81LP/W

And which one would be better for my PSP? or are the ones included in the value pack good?

 

[penceman]

WTF?

 

[Mysteriouskk]

do you have any suggestions, headphones or earphones that would work great with the PSP?