Opteka TTL Auto-Focus Dedicated Flash Speedlite (IF-500) for Panasonic Lumix DMC G7, GX8, GM5, GH4, GX7, G6, GH3, GH1, GF1, GH2 and GF2 Micro Four Thirds Mirrorless Digital Cameras Compatible with Panasonic micro four thirds digital cameras featuring TTL support Guide number at ISO 100 of 130' at 105mm TTL, RPT and Full manual control option from 1/1 to 1/128 power Recycle time of 0.2 to 6 seconds Exposure compensation from -3 to +3 EV