Review on 📚 EduSoho Bamboo Laptop Bed Tray Desk - Adjustable Lap Desk with Storage Drawer, Cup Holder & Cooling Fan for up to 15.6 inch Laptops - Ideal Laptop Stand for Bed by Kendrick Barron

Based on the reviews it's more of a 3.5 than a 4. It's very smooth. If you put something smooth on it, expect it to slip off instantly when you move it. My main meat is flat, the "cup holder" is just a little indentation, it's more of a suggestion of where to put the cup. And I think I prefer something deeper so my cup doesn't slip off. It is height adjustable from the lower legs as well as under the surface to tilt the laptop. So I think using my laptop in my bed is an overall success.