Need to correct this -- on occasion I come across new old stock OEM ear socks and I sell those (am currently sold out). The Ear Socks on the OXM website marked "OXM" are aftermarket production -- however, I went to the extreme to get both the proper size, proper markings exactly like OEM and a high grade moisture wicking rubber that will perform like OEM.OXM is not making socks himself. The stuff he's selling is also OEM.
Like OEM socks, you'll need some lube to get them on the ear stems (I use Purell Gel hand sanitizer for this).
Also, another poster is correct that some older Romeo 1 ear socks that the reps had in their kits did not have any markings on them.