This item, purchased June 24, 2016. Can provide receipt to serious buyers.
https://www.amazon.com/Microsoft-Sculpt-Comfort-Desktop-L3V-00001/dp/B00CYX53QW/

Like new condition, not used much. Missing a prop up tab. Works with Mac and PC. Comes with batteries. Contact through email, cash only, pick up from Palo Alto. Thanks for looking.