Yes, you can use the Westcott FJ400 II 400Ws Touchscreen Strobe with FJ Pro AC/DC Battery on AC via the AC power cord that is provided.

The Westcott FJ-X3 M Universal Wireless Flash Trigger is equipped with multi-brand technology that pairs with most camera brands to trigger the FJ Wireless and Canon RT devices. This 2.4 GHz remote offers revolutionary compatibility with many Canon, Nikon, Sony (with adapter), FUJIFILM, Panasonic Lumix, and Olympus cameras.

The Westcott FJ400 II 400Ws Touchscreen Strobe with FJ Pro AC/DC Battery (B&H# WEFJ400IITSS) has a standard 3.5mm sync port that may be connected to many brands of radio receivers such as the PocketWizard PlusX Transceiver (B&H# POPWPX). Of course, only appropriate Westcott transmitters such as the Westcott FJ-X3 M Universal Wireless Flash Trigger (B&H# WEFJX3MWFT) whose signals are received by the FJ400 II's own internal receiver will support TTL, HSS, and remote intensity adjustments.

Yes, the monolight strobes in the Westcott FJ400 II 400Ws Touchscreen Strobe with FJ-X3 M Universal Trigger (2-Light Backpack Kit) have a Freeze Mode feature. As indicated on page 15 of the instruction manual, when you are on the [MENU 2] screen, under the [SYNC] tab will be the option to set the monolight to [Freeze Mode], which allows you to capture fast-moving subjects with an ultra-short flash duration to stop motion effectively. Do note this is only available in Manual Mode only.

The Canon RT frequency has become overcrowded in the last few years and Canon has not been able to provide a stable frequency for communication, leading to missed shots and connection loss. Therefore, for best performance we recommend either the FJ80 II or FJ80 SE Speedlights.