The Emperor’s New Sleeves aren’t so much a piece of clothing as they are a visual lack of clothing. It’s a nice way of giving the bare-arms look to an outfit on races other than an Opifex (who by default have bare arms on the “naked” model).
They are wearable by free players, but you need the Alien Invasion expansion pack to buy the kit. The finished sleeves are not available from the Phasefront Paid Points Vendor.
To make them you will need to pick up a few items. Fashion Kit – New Sleeves can be purchased from Maria’s Fashion terminal inside of Uncle Bazzit’s Workshop in Meetmedere. To make the base sleeves you will need Light Bio Mesh and Anti-Perspiring Padding, both are rewards from quests starting with Master Divenchy outside of Newland City.