Really handy to put a 70w, 100w, 140w adapter closer to where you need it. Should work with every Apple adapter with removable prongs.
Not a big deal because it will work anyway, but just important to note that this is a refurbished cable that is third party. Not OEM Apple. The one I received was heavily scuffed and had debris around the plug. It is Volex brand, not Apple.
Contact support. Mine appears genuine Apple. The product description is for an Apple product:
“Apple MK122LL/A Power Adapter Extension Cable“
Oh, it says Volex on one end, Designed by Apple in California on t’other.
When I got mine I wiped with a clean damp rag, cleaned right up.
As @davidbspalding noted above, they are Apple cables. The vendor confirmed they are Apple cables,with Volex on one end & Designed by Apple on the other.