This is a 21" Mole-Richardson Half Single Wire Scrim for the Tener Solarspot.
Scrims are stainless steel or wire mesh screens that fit into retaining rings in front of a light fixture to diminish the light output without dimming the fixture and subsequently changing the color temperature. The scrim reduces the output by about 1/2 stop over half the light beam.
This is primarily of use when filming a subject moving towards an elevated fixture pointed down. Placing the wired half of the scrim at the bottom of the beam prevents overexposure as that subject moves closer to the light.