The Fujifilm EF-42 flashgun is a TTL flash which is perfect for use with the Fuji Finepix HS20, X-T1, X100 & X10 digital cameras. Guide number of up to 42 (ISO 100, m). Bounce & swivel head with auto zoom function. EV & power ratio can be manually adjusted in 7 steps. AF assist light for when shooting in dark or low light scenarios. Powered by 4x AA batteries.