In layman's terms that's more than 2-3 stops what a Nikon/Canon will sync (in reality, not the listed 1/250th white paper specs).
Which means you're able to turn down that sunny-16 (f/16) sunlight down to f/8 or f/5.6.
How do leaf shutters work?
Provides information on lighting design related to different lighting situations, such as architectural lighting and theatrical lighting.