Lenovo ThinkPad X1 Yoga Gen 4 review: The first aluminum ThinkPad is a winner - Neowin
mCover Case Compatible for 2019~2021 14" Lenovo ThinkPad X1 Yoga Gen 4 / Gen 5 Series 2-in-1 Notebook PC ONLY (NOT Compatible with Any Other Lenovo Models ) - Black : Amazon.ca: Electronics
ThinkPad X1 series - Wikipedia
Lenovo ThinkPad X1 Yoga (4th Gen) review: Thinner, lighter and still the best 2-in-1 for business - CNET