I just bought a new iMac and no longer need my Thunderbolt Display. It's worked great as an external display for my Macbook Air (I had to use a Thunderbolt 2 to 3 adapter which I will also include).
*BONUS* I will also include my Magic Keyboard and Magic Mouse if you need them! They are both in great condition, about 4 years old.
Specs:
Resolution: 2560 x 1440 QHD (16:9 aspect ratio)
Panel Type: LED-backlit IPS LCD with glossy finish
Brightness: 375 cd/m2
Response Time: 12 ms
Audio: Built-in 2.1 speaker system (49W)
Camera: Built-in FaceTime HD camera with microphone
Mounting: Standard stand with 30° tilt (no height adjustment), VESA mountable
Included Cables: Thunderbolt (1/2) connector and MagSafe (1) charger.
Rear Ports: 3x USB 2.0 ports, 1x FireWire 800 port, 1x Gigabit Ethernet port, 1x Thunderbolt port