The TP-Link TL-MR6400 is a wireless router with a SIM card slot that supports 4G LTE connectivity. It provides a maximum wireless speed of up to 300Mbps, making it suitable for small to medium-sized homes or offices where internet access is primarily through a cellular network.

Key features of the TP-Link TL-MR6400 include:

1. 4G LTE Connectivity: The router supports 4G LTE networks, allowing you to insert a SIM card from your mobile carrier to access the internet.

2. 300Mbps Wireless Speed: The router offers a maximum wireless speed of 300Mbps on the 2.4GHz band. While not as fast as some high-end routers, it provides decent speed for everyday internet activities.

3. Ethernet Ports: It includes multiple Ethernet ports (typically four LAN ports) for wired connections to devices such as computers, gaming consoles, or smart TVs.

4. SIM Card Slot: The SIM card slot enables you to use a SIM card to establish a 4G LTE connection, eliminating the need for a traditional broadband connection in areas with good cellular coverage.

5. External Antennas: Some models of the TL-MR6400 come with external antennas, which can help improve wireless coverage and stability.

6. Guest Network: You can set up a guest network to provide internet access to visitors without sharing your main Wi-Fi network password.

7. Parental Controls: The router may offer parental control features, allowing you to manage and restrict internet access for specific devices or users.

8. Easy Setup: TP-Link routers typically have an easy setup process through a web interface or mobile app, making it user-friendly for most consumers.

When considering this router, it's essential to verify the specific features and capabilities based on the model and firmware version, as manufacturers may update specifications or offer different variants over time. Overall, the TP-Link TL-MR6400 is a reliable choice for users looking for a 4G LTE-enabled router with decent wireless speeds and essential networking features.