Anarchy's Children introduces more than 100 new "exotic" soldier customization options, including more hairstyles, face paint, armor, decals, helmets and masks, among other items.
Anarchy's Children included with XCOM 2's $20 Reinforcement Pack or it can be purchased by itself for $5. Two further add-ons, Alien Hunters and Shen's Last Gift, will be released this summer.
Firaxis also said it will release a new patch for XCOM 2, presumably alongside the DLC, that will introduce "performance optimizations" and gameplay fixes. More details will be announced "very soon."