BioWare posted a new blogpost on a new feature in the game: Weapon Tunings. This can be used to customize your weaponry, creating a brilliant visual flair on the weapon itself!

If you want to equip a Weapon Tuning the first thing you’ll need is a weapon with an available Tuning Slot. Weapons that have a Tuning Slot come from many different sources including the Cartel Market, PvP, Operations, Reputation Vendors, Flashpoints, Heroics Missions, and Crafting Recipes. Be sure to check if your Weapon has a Tuning Slot!