Canon 600EX-RT Speedlite. I'm selling this because I switched camera brands and no longer use it. The drive mechanism is in perfect working order. The strobe functions without any issues. Please note that the bounce and diffuser parts are missing. This is suitable for those who will use the strobe directly or with ceiling bounce. I will sell it as is, including the stickers. I've priced it lower than the market average, so if the conditions suit you, please consider it.