Nikon SB-R200 Remote Speedlight Functions only as a remote Speedlight unit Auto FP High-Speed Sync; use with fast shutter speeds achieves effective blurring of out-of-focus background elements FV lock holds flash value, enabling re-composition prior to shooting Electronic Construction - Automatic Insulated Gate Bipolar Transistor (IGBT) and series circuitry (for wireless remote flash only) Guide Number - 10/33 (ISO 100, m/ft), 14/46 (ISO 200, m/ft)