Phottix Odin TTL Wireless Flash Trigger for Nikon - Receiver 2-Pack (PH89057) Wireless 2.4GHz TTL and manual flash triggering Range of 328ft Access to 4 Channels and 3 Groups Maximum Sync Speed of 1/8000 Second with High Speed Sync Compatible with Phottix Strato II and Atlas II Wireless Radio Flash Triggers