Unit is being sold for parts or repair, and does not currently appear to operate as expected. Unit includes one two batteries, but one is not functional as a result of the gold contact tabs peeling/flaking away due to time and corrosion. The tab on the body of the unit that locks batteries in place has broken off, but batteries still attach securely enough for use if unit isn't being shaken violently. Unit includes the pump head and non-pump head, and is able to power on and recognize each without issues. When unit attempts self-test without the pump head, it shows a methane error before giving readouts that appear accurate. When pump head is attached, unit moves to the "block intake" step before showing a self-test failure and giving measurements that appear accurate. Unit includes paperwork, CD, and charging stand. Please see pictures for an exact idea of condition - notable scratching and signs of previous handling. Will be shipped same or next day by an experienced seller.