After testing, it will not affect the WIFI signal. Increasing the large Cooling column allows for better heat dissipation. Increase the power cooling column to bring better heat dissipation to your for Raspberry Pi 3B/3B+. No longer worry about overheating. There is no need to install a fan. It also provides perfect heat dissipation. Durable, hard, long-lasting rust-free, wear-resistant, and can be well protected to your for Raspberry Pi 3B/3B+. All ports and slots of the case can fit perfectly with for Raspberry Pi 3B/3B+ size:9.1x6.5x3.6cm Material:Aluminum alloy colour:black Package Contents: 1 * Aluminum Alloy Cooling Case 1 * Screw Set Only the above package content, other products are not included. Note: Light 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.