 "16 Rods Octagon Softbox with Grid for Bowen or Alien Bee Monolight Strobe Studio"
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The 16 Rod Octagon softbox is an essential light modifier for 
commercial, fashion, and portrait photographers. This parabolic softbox 
is designed to produce a beautiful soft round light with a natural 
vignette.  It features a deep parabolic construction creating stunning, 
wrap-around light.  The dual layer inner diffuser helps eliminate hot 
spots for even lighting and very smooth fall-off.  Choose the  version 
of the softbox with the grid for even finer control of the spread of 
light.Dimensions: 36" Diameter x 24" Deep" 
 "3 in 1 Stacking Grid Light Modifier System for CANON 580EX/ 580EX II Flash Speedlite, SG-C GRID"
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The Light Modifier was designed to produce 3 different size of light spread (Small, Medium and Large) and when aligned and stacked two grids together, produce the smallest spots of light. Stack the small grid into the bezel to produce large size spots of light, for medium size spots of light just stack the larger size grid into the bezel." 