This hotshoe mounted optical flash trigger provides automatic TTL Flash when used with Inon S-TTL and Sea & Sea DS-TTL Strobes connected by fiber optic cables. The TTL trigger also offers manual triggering, including rear curtain sync, with any compatible slave strobe. Accurate automatic TTL flash exposure has been a favorite feature of Nauticam photographers using cameras with pop up flashes, and Nauticam is excited to bring this advanced flash control functionality!