Accessories difference for these headphone adapters

[chicago]

can someone please explain the difference between these adapters. 2.5 vs 3.5 vs enhanced usb ect.. here is a link for a bunch of them

http://www.g1depot.com/g1-adapters.htm

 

[Pathosis]

if you're using standard headsets (like ipod headphones).. just get the 3.5 mm. all you needa know