I have a pair of RE400 in great condition up for sale. I have done the foam mod on these, which involved removing the filter, removing the small circular piece of foam shown in the photo and putting on two filters per side. I got the idea from user Deni5, page 29 of Upcoming Hifiman IEM's: RE-400 and RE-600 thread. This increased treble presence and made them more likable imo. It is possible to reverse this mod, put back foam pieces and 1 filter per side.
Biflange tips on the iems are used and will not be included unless you are ok with cleaning them with rubbing alchohol to have a pair of backup tips.
Reason to sell:
Funding for TF10 reshell
Feel free to message with any questions,
Asking $85 PP (fees included) + Shipping