D-Link 4G LTE (Cat 4) to Gigabit Ethernet Modem/Bridge, Best for M2M Applications, Supports OpenVPN, Optional Enterprise Service Platform, Works on Verizon or AT&T (DWM-311-B1)
Access to a Raspberry behind a 4G router through a VPN tunnel - OpenVPN Support Forum
D-Link
KuWFi 4G Router with SIM Card Slot Unlocked, 1200Mbps LTE Router Dual Band Gigabit Cellular Router with External Antenna, EC25-AF Module Support DDNS/ VPN/QoS, Up to 64 Users[with 1G LTE Data SIM Card]
4G LTE Industrial Mobile VPN Wi-Fi Router Indonesia