What is this slot for on my motherboard? It's a Micro Star Pro z790a I

microstar slotSelamat Datang Di Situs Terpercaya MICROSTAR88 || Tersedia Deposit Via Pulsa, E-wallet & Semua Jenis Bank Indonesia || Bank On 24 Jam ( Kecuali Gangguan ) || Selamat BermainMINI FAN PORTABLE + SLOT USB TRISONIC Kipas angin portable ini mudah dibawa dilengkapi lampu LED, dicharge dgn USB. Merk. Trisonic Size.150x120x44mm.