I purchased this new, but did not realize that it will not work for the size of lawn we have. This unit is brand new, but the box has been opened. Paid over $1600
Landroid 28-Volt MAX* Cordless Electric Robotic Lawn Mower

The engineers at WORX created Landroid, the unmanned mowing vehicle, with the following philosophy in mind: Because you have better things to do. Landroid is the first intelligent robotic lawn mower and it will change your life. An intuitive and user-friendly interface lets you easily and quickly customize your mowing schedule. But don't worry, Landroid comes pre-programmed and ready to use right out of its box. Landroid receives its brainpower from the Advanced Intelligence Algorithm (AIA) that allows it to perform intricate cuts and navigate narrow passageways with ease. And since no two yards are alike, Landroid is able to learn the nuances of your yard and treat different sections with different cutting options. The powerful and adaptive brain and motor combine to tackle hills and uneven terrain like a champ, factoring in elements like drift, incline, and other parameters to evenly mow up to a 20° incline or decline. All this in a low-noise, zero emissions package that allows you to enjoy the yard space even while Landroid is doing its thing.

Pre-programmed and fully automated for easy use right out of the box
Artificial Intelligence Algorithm (AIA) allows Landroid to perform intricate cuts and navigate narrow passageways
Intuitive user-friendly interface makes it simple to customize mowing schedules
Handles hills easily, mowing uneven landscapes with up to 20° inclines/declines
Automatically returns to charging station when battery is low
Rain sensor sends Landroid back to the charging station when it's raining
Shock sensor system helps avoid obstacles in your yard, protecting Landroid and your plants and flowers
Anti-theft system uses security PIN and alarm to prevent unauthorized use
Tilt/Lift safety sensors shut down motor as an added safety precaution
Specifications:

Deck Width: 22-in
Cut Width: 7-in
Cut Height Adjustment: 9-position
Bagger Included: No
Discharge Location: Rear and side
Mulching Capability: No
Transmission Type: Self-propelled
Brushless: Yes
Removable Battery: Yes
Battery Type: Lithium-ion