The Nanlite FL-20G Fresnel Lens is a glass Fresnel lens with an adjustable-length housing that focuses light output. It includes metal barn doors and features a Bowens Mount. It's compatible with the Nanlite Forza 720, 720B, 500 II, 300 II, 300B II and the FS-Series spotlights. It's also compatible with the first-generation Forza 500, 300, 300B, and 200. Dial-In The Beam Angle The FL-20G's rotating barrel design enables beam angle adjustment from spot (10°) to flood (45°) with an intuitive twisting motion. Increase Brightness For example, when set to a 10° spot the FL-20G can increase light output of the Forza 300 to 128679 Lux at 1 meter and the Forza 500 to a staggering 217649 Lux at 1 meter. Thermal Management The FL-20G's material design was specifically created to handle the heat output of Forza lights running at full brightness without any adverse effects. Includes Barndoors The included metal barn doors enable further adjustment of the light output and control of spill. Quick Change Modifier Mount To keep up with the speed of production Nanlite kept the modifier mount fast and simple. With one push of a button and a quarter turn, you can swap out the FL-20G for any light modifier using a Bowens Style mount, including but not limited to Nanlite's own line of light modifiers.