The ARK (also spelled Ark) is a barrel attachment found in the Extinction maps Awakening and Exodus. It allows weapons to turn into a laser weapon, though it still uses conventional ammunition and also has the additional effect of causing extra damage to cryptids, which further makes any that are killed with the weapon it's attached to explode in a similar fashion as to the Pipe Bombs.
A kidney, ureter, and bladder (KUB) study is an X-ray study that allows your doctor to assess the organs of your urinary and gastrointestinal systems. Doctors can use it to help them diagnose urinary disorders and causes of abdominal pain.
X-ray beams are passed through the abdomen, producing images of the kidneys, ureters, and bladder on a special type of film. KUB radiography is often used as a first step in diagnosing problems of the urinary system, and is usually done in conjunction with intravenous pyelography.