When you need maximum coverage in a single flash, the AC Bare Bulb Slave delivers. This AC flash features a U-shaped flash tube firing into a diffused dome for broad coverage. Because of the unit's small size, the output still has fairly high contrast, and is ideal to light backgrounds for environmental portraits. Specially designed to deliver even light to the widest area, the Bare Bulb Slave also makes an excellent general coverage light. When used for portraiture, it delivers a slightly softer light than the other AC's. It can also be used to full advantage to replace standard household light bulbs in architectural interiors. Like the other AC's it is triggered by your main flash unit through a built-in slave sensor. It has a guide number of 26 with ISO 100 film and recycles in 5 seconds.