Feature: CNC precision manufacturing, sandblast anodic oxidation process Ultra-thin design, only 13mm thick, highly portable. Perfect support 40 pin GPIO Ribbon Cable The status light is visible, WiFi and Bluetooth function of for 4 Model B is available. Passive cooling architecture design, the aluminum alloy case have good heat dissipation, support CPU and memory heat sink. Ultra-thin design made the case highly portable, the case only 13mm thick, thick 23mm when assembled with for 4 Model B All ports and slots of the case can match with for 4 Model B perfectly. Specification: Applicable model: for 4B Material: aluminum colour: Black Package Contents: 1 x Protective Case 1 x Screwdriver 4 x Anti-slip rubber 4 x Screws 3 x thermal silica gel Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.