Review on GeeekPi 4-Layer Cluster Case for Raspberry Pi 4, with Cooling Fan and Heatsink, Acrylic Rack Case Stackable for Raspberry Pi 3B+, 3/2 Model B by Amicz Kakaruk

This is the worst Raspberry Pi case I have ever used. The layers of plastic are so brittle that if you tighten the fastener even a little harder than "by hand" (e.g. just with your fingers), the plastic will tear somewhere. And as more layers are added, it's likely to crack somewhere, even with "finger tightening". The acrylic used is too thin and too brittle. Save hours of wasted time and pay an extra $20 for a properly assembled case.