This is an ARRI Full Double Scrim that fits the 650W Fresnel, Arrisun 2, HMI 200W or any fixture that accepts a 6 5/8" accessory. Scrims are metal screens mounted in a metal frame. They are placed in front of a light to reduce light intensity. ARRI makes four different types of scrims:
Full Single: This scrim covers the entire lightface and reduces the intensity of the entire light beam.
Full Double: This scrim covers the whole face of the light. It has two metal screens in it, reducing light intensity by two times the amount of the full single.
Half Single: This scrim only covers half of the lightface reducing half of the light intensity.
Half Double: This scrim is the same as the half single but reduces light intensity twice as much.
Half scrims may be rotated in position for more precise control.