For Lenovo ThinkPad X1 Carbon 2nd Type 20A7 20A8 touch screen models &
Lenovo ThinkPad X1 Carbon 3rd 20BS 20BT touch screen models only
This Rear Cover Upper Case/lid is for the thicker touch screen panel versions X1 Carbon 2nd/3rd Gens only
This rear cover has 3x brass screw ferrules either side (non touch versions have 4x brass screw ferrules either side)
Do a visual check of exactly what your rear cover is before buying to avoid ordering wrong part.
Thanks for looking :-)