HP U160 Portable 15" Monitor. Connects via USB-A. It's a great monitor with leather backing and about the size and weight of a beefy laptop. I used this for years while consulting and needing an extra monitor for the work I was doing. I've switched to fully remote and now have more permanent monitors for my desk so there's no need for this.
It has some minor cosmetic bumps and bruises but the screen is still in great shape with no cracks or worn pixels. It folds and unfolds easily and the magnetic flap still holds tight.
This monitor still retails for around $100 last time I checked Amazon.