This is the Litepanels 45° Honeycomb Grid for 1X1 LED Lights.

Litepanels' honeycomb grids, compatible with all models of 1X1 fixtures, offer convenient means to control the LED light beam. Constructed of extruded ABS plastic with powder-coated aluminum honeycomb material, they're available in 90, 60, 45 and 30° versions, with 30° offering the tightest control of the beam. In practice, the grids, which slide into the 1x1's accessory rail system, function much like barndoors to control spill light, while their 3/4" depth is consistent with the slim-profile design which is the hallmark of Litepanels products.