Pi add-on offers M.2 for 5G and mini-PCIe for 4G and NB-IoT
Quectel Rm500q Adapter | Pcie Adapter Modem | Mini Pcie Quectel | Mini Pcie Modem - 5g Mini - Aliexpress
Dual Gigabit Ethernet 5G/4G Mini-Computer Based On Raspberry Pi Compute Module 4 (NOT Included), Metal Case, With Cooling Fan | CM4-DUAL-ETH-4G/5G -BOX
Wholesale Mini PCIe PCI-E (USB3.0 Signal) Interface to NGFF M.2 Key B Wireless Adapter with SIM Card Slot For 3042 3052 5G 4G Module Modem From m.alibaba.com
SIM8200EA-M2 Industrial 5G Router, Wireless CPE, Snapdragon X55 Onboard, Gigabit Ethernet And WiFi, 5G/4G/3G Support
Amazon.com: HLT M.2 (NGFF) Key B to Mini PCI-E Adapter with Dual Nano SIM Card Slot : Electronics
Quectel Rm500q Adapter | Pcie Adapter Modem | Mini Pcie Quectel | Mini Pcie Modem - 5g Mini - Aliexpress
Timack M.2 Key B to Mini Pci-e Adapter 5G ,M.2 Key B to Mini PCI-E Adapter : Amazon.in
Sierra Wireless Em9190 M.2 5g Module With M.2 To Mini Pcie Adapter - Iot Accessories - AliExpress
Mini-PCIe to M.2 (NGFF) Key B 4G 5G Modem Adapter - The Wireless Haven
Source LTE 5G Module with Mini PCIE Hardware Interface on m.alibaba.com
Jinveno M.2 Key B to Mini PCIe Adapter w/ 2 NANO SIM Card Slots for 3G 4G 5G Module | Walmart Canada
Test Quectel EC25-A LTE Cat 4 mini PCIe module · Issue #344 · geerlingguy/raspberry-pi-pcie-devices · GitHub