Features: Manage your RPI you will be able to see and access all ports onboard your RPi and set cable alignment simply and with ease.The flat top roof is perfect for affixing a USB hub, heat sink or switch. Easily insert or access cable, SD card, audio input, GPIO pins. for 4 Model b /3 Model B+/ Pi 3b/ Pi 2B. Access to all GPIO ports ,semi-enclosed cases allow easy access for all features an add-on, including the USB ports, flex cable, camera module, etc. Not only elegant design, but also very high transparency.You can clearly see 3B+ through this for shell, which will not stop you from observing RPI changes. The highest can be stacked up to the 4 layers.According to your needs, the number of stacked has your decision.1- layer, 2- layers, 3- layers, 4- layers. Specifications: Material: Acrylic board Size: 10x7.54cm/3.94x2.95inches Layer: 1 layer /2 layer/3 layer/4 layer Package Includes: 1Set x Multilayer for Shell Kit note: No retail package. Please allow 0-1cm error due to manual measurement. pls make sure you do not mind before you bid. Due to the difference between different monitors, the picture may not reflect the actual color of the item. Thank you!