The Omnicell is ideal where an auxiliary flash cannot "see" the light from the main flash. The Omnicell plugs directly in to any compatible flash unit, providing a clear position which can now caprture the main light source. An ideal accessory for the Travelite system when the photocell is blocked, or positioned where the main light cannot reach. The Omnicell is compatible with a 1/4" (0.6cm) phone jack.