Amazon.com: Nanopi R5C Mini WiFi Router OpenWRT with Dual PCIe 2.5Gbps Ethernet M.2 WiFi Bluetooth Ports 4GB LPDDR4X RAM Based in Rockchip RK3568B2 Soc for IOT NAS Smart Home Gateway (with M.2
PCI Express to Dual PCI Adapter Card PCIe X1 to Router Tow 2 PCI Slot Riser CaA5 | eBay
TP-Link WiFi 6 AX3000 PCIe WiFi Card (Archer TX3000E), Up to 2400Mbps, Bluetooth 5.0, 802.11AX Dual Band Wireless Adapter with MU-MIMO,OFDMA,Ultra-Low Latency, Supports Windows 10 (64bit) only Wireless Adapters - Newegg.com
Banana Pi quad-GbE router SBC features M.2 and five mini-PCIe slots with SIM
Mikrotik Ccr2004-1g-2xs-pcie Integrated Nic Router - Iot Accessories - AliExpress
RouterPi - A Compute Module 4 Router | Zak's Electronics Blog
Samlinking D240 Mediatek MT7620A Router Boards Support Two 4G LTE mini PCIe Modules, PoE for $38 and Up - CNX Software