This achievement is currently not available in the Guild Wars 2 API and you are seeing the last known version. The achievement has either been removed from the game or needs to be rediscovered.
Part of What Lies Within Objectives Unlock 18 Special Ops armor skins.
Tiers Objectives 6 12 18 Total Achievement Points 1 3 6 10
Rewards Data {"id": 5686,
"name": "Special Ops Armor Collection",
"description": "",
"requirement": "Unlock 18 Special Ops armor skins.",
"locked_text": "",
"type": "ItemSet",
"flags":
["Pvp", "RepairOnLogin", "Permanent"
], "bits":
[{"type": "Skin",
"id": 11338
}, {"type": "Skin",
"id": 11287
}, {"type": "Skin",
"id": 11337
}, {"type": "Skin",
"id": 11329
}, {"type": "Skin",
"id": 11272
}, {"type": "Skin",
"id": 11345
}, {"type": "Skin",
"id": 11327
}, {"type": "Skin",
"id": 11335
}, {"type": "Skin",
"id": 11318
}, {"type": "Skin",
"id": 11269
}, {"type": "Skin",
"id": 11263
}, {"type": "Skin",
"id": 11260
}, {"type": "Skin",
"id": 11315
}, {"type": "Skin",
"id": 11264
}, {"type": "Skin",
"id": 11334
}, {"type": "Skin",
"id": 11332
}, {"type": "Skin",
"id": 11348
}, {"type": "Skin",
"id": 11289
} ], "tiers":
[{"count": 6,
"points": 1
}, {"count": 12,
"points": 3
}, {"count": 18,
"points": 6
} ], "rewards":
[{"type": "Item",
"id": 99767,
"count": 1
} ] }