You can see and access all ports onboard your unit compatible with Raspberry Pi and set cable alignment. The flat top surface is for affixing a USB hub, heat sink or switch. You can insert or access cables, SD cards, audio inputs, and GPIO pins through the case. This case is compatible with current Raspberry Pi models including Pi 3 B+, Pi 3 B, Pi 2 B, Pi B+. You can see the unit compatible with Raspberry Pi 3B+ through this case, which does not obstruct observation of changes of the unit compatible with Raspberry Pi. The case can be stacked up to 6 layers maximum. You may decide the number of layers to stack based on your needs: 1 layer, 2 layers, 3 layers, 4 layers, 5 layers or 6 layers. No tools are required to complete installation of the transparent case compatible with Raspberry Pi. Installation steps: 1. Remove the film from each acrylic panel. 2. Select an ordinary acrylic panel and fix the control board compatible with Raspberry Pi with screws and plastic spacers. Repeat this step according to the number of layers you need. 3. Select one acrylic panel fitted with the control board compatible with Raspberry Pi as the bottom layer. 4. Take the short copper columns and long copper columns from the included top screw set to fix the bottom layer. The side of the board compatible with Raspberry Pi faces up, with the short copper columns positioned at the bottom. 5. Stack acrylic panels fitted with other control boards layer by layer using long copper columns. 6. Select the acrylic panel printed with the logo compatible with Raspberry Pi as the top layer, and fix it with copper nuts. 7. Assembly is complete. Colour: Transparent Material: Acrylic Size: 12x8.5x19cm Package Contents: 7 x Acrylic plate stack (with matching screws)