This compact, slim flash is designed specifically for the GR IV. It features a super-compact body for outstanding portability, small enough to carry in a pocket while attached to the GR IV camera. When the GR IV is set the ISO Auto Flash mode, the GF-2 allows the camera to automatically adjust its guide-number and ISO sensitivity settings according to the subjects distance. This flash mode enhances the GR IVs snapshot operations in casual flash photography.