The ASUS ThunderboltEX 4 is an add-on card that brings Thunderbolt 4 connectivity to compatible ASUS motherboards. It offers 40 Gbps bi-directional bandwidth, supports USB4 devices, and includes DisplayPort 1.4 for 8K video output. The card allows for daisy-chaining up to five Thunderbolt devices and provides up to 100W of USB-C charging for laptops.