This has bothered me for some time now. Every elder is running around in it and I can't locate it anywhere. Anyone know where it's from? I think it's a store item.

That's odd, I'm playing a lepacy atm and I use "Sim Game Selector" to untick certain expansions, and I'm only on generation Late Night so I don't even have Into the Future installed atm :S
edit: I have 6 pieces of CC clothing (just made the biggest clean up ever) and no sims3pack clothing either. Wheeeeeere is this coming from

I think that's the outfit from the Quantum Powerpack that came as a separate download with the limited edition of Into The Future. The outfit and all its parts (boots, accessory) have all been set to random. So you'd either need a mod that edits the resource and makes it unavailable for random outfit generation, a mod like Dresser that lets you blacklist the outfit or uninstall the pack.

Edit: Or use the override that I've attached now. It's a simple CASP edit, it goes into your Packages folder if you've installed the Quantum Powerpack as sims3pack and into Overrides if you've installed it as *.package. It's my personal copy and I've set it such that all outfits (teen to elder, male and female) are now non-random and also hidden in CAS.
This will not affect any Sims that already wear it. You'd have to remove that manually from these Sims by loading them into CAS.

Yes, it's the Quantum outfit thing that is mandatory with the cryo pods, registration gift for ITF IIRC. And yes it have to be set to non random otherwise it's like all the elders will be spawned with this, or the hair or the boots. And if you remove a part of the outfit the damn pod won't work anymore.
lol I too hidden them from CAS -.-

Thank you guys so much! No more hip elders in my game, thank god...