Correct. It's wearing a jock strap.
Edited by Anaxilus - 6/28/11 at 4:08pm
Correct. It's wearing a jock strap.
[Animated GIF of a rabbit smashing brick into face]

@Anax, Is the housing all plastic on the 7550s?
It shouldn't be.
I know the EX600 is aluminum/ABS plastic and the EX1000 is magnesium alloy. The housing material of the 7550s aren't mentioned though.
It's metal. Not sure aluminum or magnesium though.
Hmmm that's odd it looks like plastic, also the middle section of the exterior appears to be a different material that glows a bit more. Is that plastic?
When you wear them, the section of the shell that is facing out, the middle section seems different.
Somehow I'm relieved to know this 

Nozzles- 7550 is different! 600/1000 both have the 'equalizer'/foam visible from the sound bore. The 7550 has an integrated 'neck' or ring on the inside. Can't make out whether it is using the same foam as the others. Could be for increased durability, no idea on sonic impact.
Mid-section don't seem different to me, buddy.
OK, to get this right... The 7550 also has the Multi-Layer diaphragm technology... In the worst case, it's the EX600 with slightly different vents and a different inner-nozzle thing.
Apparently you can gently pull the foam out of the nozzle. That was done on the EX700 so I'm not sure about the new line-up, but the nozzles look pretty much the same. ClieOS has a post about shoving Etymotic Green Filters into these Sony nozzles.
It should be just glossy vs. matte. Like a section of the metal has been "sanded". Or else the lettering will not stand out. Too much reflection.
Also seriously, the 7550 looks like pancakes. I'm not joking. The Denon D7000 looks like a piece of cut moon-cake. Red bean fillings.