The ELB 500 TTL: Creativity, Unencumbered. Stay Focused on Storytelling, Regardless of the Situation Be prepared for any adventure with the portable and incredibly efficient Elinchrom ELB 500 TTL. Combining 500 Ws of power with features including TTL, HSS, Active Charging, and Full Asymmetry all in a package weighing only 8lbs, this robust off-camera flash enables you to create freely in the studio, on location, or even on the move. Travel Light Weighing only 1.5lbs, the ELB 500 TTL's Flash Heads can be easily boomed out by hand or with minimal counterweight. The compact design eliminates the need for heavy-duty stands and enables the ELB 500 TTL to be comfortably worn by an assistant. And Stretch Your Imagination Achieve sync speeds of up to 1/8000ths of a second using High-Speed Sync to freeze motion with incredible sharpness, create a narrow depth of field, or overpower the sun. With Independent Remote Control of Up To Two Flash Heads Take full advantage of the ELB 500 TTL's fully asymmetric power distribution with an Elinchrom Skyport Transmitter Pro. Now you can independently adjust each head's power across their seven-stop range and control the modeling lamps from atop your camera. So You Can Master Your Workflow The ELB 500 TTL lets you compose images at the speed of life. Use TTL to set an exposure quickly and then use Manual Lock to switch to manual mode without losing your initial exposure for further adjustment or to explore creative effects. Never Lose Momentum The ELB 500 TTL's Active Charging enables you to plug into AC power and charge the battery mid-shoot regardless of the batteries' charge level, making it perfect for an uninterrupted workflow. And Transform Your Lighting ELB 500 TTL flash heads utilize Elinchrom's Q-Mount (formerly known as Quadra Mount) for seamless compatibility with Elinchrom's line of super-portable Snaplux series of softboxes. They can work with any other Elinchrom light modifiers and accessories, including Rotalux and Litemotiv softboxes, via the Quadra Reflector Adapter MK-II (EL26342) sold separately. With Advanced Battery Technology The Elinchrom ELB 500 TTL Battery is s 14.4V, 5Ah, 72 Wh Li-Ion battery designed to be used exclusively with the ELB 500 TTL. This battery can generate 400 full-power flashes from one charge and a fast recycling time of 2 seconds at max power. It was engineered to have no memory effect, meaning charging to be started or stopped at any level with no negative impact.