okcsc ETYMOTIC Male to QDC 2PIN Female Headphone Adapter for ER4SR Earbuds to QDC 2 PIN Cable Lossless Audio Adaptor for Etymotic ER4SR ER4XR ER3XR ER3SEER2XR ER2SE LNO08099 KZ ZSN ZS10 1 Pair Black

Doesnt work, even though they look similar i found out the hard way they are not compatible PS: I made it work by using sandpaper on the ER2XR, still going to leave this review with 1 star because I shouldn't have to physically modify my equipment to make a product compatible when it advertises compatibility without any modification needed.

These adapters work electrically, but the right-angle design has an annoying limitation: the pair is not mirrored in a way that preserves polarity while also letting both sides point inward. On my 2-pin IEM cable, the polarity is symmetric on both left and right. With these adapters, keeping the polarity correct makes both right-angle MMCX ends point the same absolute direction. If I flip one adapter to make them both point inward toward my ears, the polarity reverses on one of the sides, which is incorrect. Mismatched polarity breaks stereo imaging, reduces bass response, and ruins center focus. Vocals and centered sounds no longer lock into place, and the sound becomes diffuse and hollow, especially on tracks with strong mono bass or centered vocals. So they may technically work, but for most 2-pin IEM/cable setups you cannot get both correct polarity and ideal left/right fitment. A true mirrored L/R adapter pair would be better. I would only recommend these if you are okay checking polarity with a multimeter and possibly accepting awkward cable routing.

Like the other comment said, does not fit ER2XR dispite it being advertised as such. Disappointed.

These are not cheap adapters, but I have not seen a ton available for sale, so if you need them... Also, the quality is top notch. Recommended for need.