PHAT-NBIOT - Designer Systems - LTE CAT NB1 MODEM MODULE, RASPBERRY PI ROHS COMPLIANT: YES
Sixfab Raspberry Pi 4G/LTE Cellular Modem Kit | eBay
Modem LTE/3g /2g with raspberry pi 3/4 A+/B+... - Hackster.io
Amazon.com: 4G / 3G / GNSS HAT Module for Raspberry Pi Zero/Zero W/Zero WH/2B/3B/3B+/4B/Jetson Nano, Based on SIM7600A-H , 4G Communication and GNSS Positioning Module Support LTE CAT4 up to 150Mbps :
3. Installing 4G USB modem to Raspberry Pi – RC Bellergy's Drones
How to fit a Raspberry Pi with mobile connectivity
Using 4G LTE wireless modems on a Raspberry Pi | Jeff Geerling