The GS400II 400Ws Monolight from Godox is a versatile flash head with solid core and convenience features. The strobe has power that's variable from 1/32 to 1/1 and recycling times from 0.3 - 1.5 sec. The 150W modeling light can be set to Proportional to mimic the effects of the flash's power setting for pre-visualizing your photo, or it can be adjusted from 5 - 100% output. Both the power and the modeling light can be adjusted remotely with the separate purchase of a transmitter, since the head has a built-in 2.4 GHz wireless receiver. The optional XT16 or FT-16 transmitter will give you triggering and control of the flash head's functions while the X1 TTL, as its name denotes, adds TTL exposure functionality to the system. Settings are visible on the flash head's digital readout. The GS400II has a Bowens front accessory mount that allows it to use not only Godox modifiers, but also accessories from the many manufacturers that use this popular mount. The GS400II ships with a tilting umbrella bracket, standard reflector, glass protection dome, and a lamp cover.