This is a 6 5/8" Full Double Scrim for the Kobold DW 400 HMI fixture or any other fixture that accepts a 6 5/8" accessory.
Full Double and Single scrims dim the light across the entire beam spread, and 1/2 and graduated scrims are used to even the beam spread when lighting a subject or background from an angle.
Keep several densities of scrims available to be prepared for any lighting situation.