The Standard Reflector for AD400Pro Flash Head from Godox measures 4.25\" in diameter and has a 110\u00b0 beam spread that makes it a good choice for use with umbrellas and various other lighting setups. The reflector has a Bowens accessory mount and a Bowens adapter is included to allow the AD400Pro to accept the reflector as well as the many light-shapers made with this popular mount.