The pic shows a C7 style upper with the A1 rear sight. So I'm assuming that's what you would get?
https://www.armsunlimited.com/Colt-M16A2-Complete-Upper-Receiver-Lower-Parts-Kit-p/risp-cur.htm
https://www.armsunlimited.com/Colt-M16A2-Complete-Upper-Receiver-Lower-Parts-Kit-p/risp-cur.htm