Equipment can be "transferred" in Aika to give the gear a different appearance. This does not change the stats or reinforcements, only appearance.
You may transfer, or skin, almost any piece of equipment with another piece; however, there are also costume skins available in the Cash Shop that give the appearance of clothes, sun glasses, bracelets, etc.
You may also change the look of your mount by purchasing a Mount Change V2 ticket from the Cash Shop for 500 gP. This allows you to change your mount's appearance into that of other classes' Traband series mounts.
To remove skins, you must purchase Purifying Ore (currently 400 gP) from the Cash Shop. This only removes skins, not enchantments.