The Visual Echos FX1 Better Beamer Flash Extender will help increase the reach of the flash and increases the flash output by about 2 to 3 f/stops. It focuses and concentrates the output of the flash into a narrow beam via the fresnel screen that gets positioned in front of the flash. This allows shooting at greater distances and shooting with smaller apertures.
The Better Beamer is designed to be used with lenses 300mm and longer, and its rugged, injection-molded plastic side supports are attached to the flash head by a sturdy elastic "hook-and-loop" band. The rigid supports hold the Fresnel screen in place in both horizontal and vertical formats. Just weighs 2 1/2 oz.
The FX1 version will fit many mid-size flash heads, e.g. Canon 430EZ, 199d, Nikon SB-24 and SB-28, Minolta 2500 and 5400, and Pentax 5000AF. The measurement between the two attachment flaps is 1 9/16".