https://www.litter-robot.com/litter-robot/accessories/litter-robot-4-carpet-tray.html
Litter-Robot 4 Carpet Tray | Use Litter-Robot 4 on Carpet
The carpet tray improves the accuracy of SmartScale™ weight readings when Litter-Robot 4 sits on carpet. (Not required for Litter-Robot 4 to function.)
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