Honlphoto 1/4" Honeycomb Speed Grid for Shoe Mount Portable Flashes Speed Grids attach quickly and easily to most portable flash units using our non-slip Speed Strap 1/8 Speed Grid has a 1/8" honeycomb cell size to narrow the beam of light from your portable flash unit, producing a small circle of light Fits most any shoe mount and most handle mount portable strobes, including Canon 420 though 580 and Nikon SB24 though SB900 Attaches quickly and easily to our Speed Strap mounting system Usable honeycomb area is 3.5" x 2.25" (appr. 89mm x 58mm)