What is the X3 antenna interface of the Hotspot?

All Models X3 LoRa interface is RP-SMA hotspot end.  

 （NOTE:EU868 Hotspot shipped before September 2021 may integrate SMA hotspot end. ）

                                                                                           X3 hotspot

NOTE1:      

       When you purchase antenna, cable and filter, you need to check and pay attention to SMA connector. RP-SMA-K to RP-SMA-J  and SMA-K to SMA-J  is ok, any other combination is wrong.

NOTE2:  

    Install the LoRa antenna on the LoRa Antenna port.Do not connect to other interfaces (such as RF)

NOTE3:

    You can purchase antenna, feeder, filter and other accessories through Cotx shop.

     COTX SAW Band Pass Filter — COTX Networks Store (cotx-store.com) 

NOTE4:

    If the connector does not match for some reason, you can purchase a third-party conversion plug to solve the compatibility problem.

    https://www.aliexpress.com/item/4000982991805.html