This new speedlite from Canon sits atop the Canon flash range, thanks to its extra-strong output and radio transmission wireless functionality. The Canon 600 EX II-RT offers an exceptional guide number of 60M at 100 ISO, making it well equipped to handle the majority of your lighting needs on the go. Continuous flash performance has been improved as has wireless functionality, with the ability to control up to 15 speedlites in 5 groups at a range of 30m, via the 2.4 GHz radio system. Compatible with Canon E-TTL/E-TTL II, the speedlite 600EX II-RT will help light up your images, but also enable you to explore more advanced lighting techniques such as High-speed and 1st & 2nd Curtain sync.