This Profoto Glass Plate for theB1, B1X, D1, and D2 Monolights lowers (warms) the color temperature of the light emitted by 300K while slightly softening the output. It approximates the use of an 81A filter on a camera lens. Use it if the color temperature is too blue for your preference or assignment requirements. This glass plate is held by 3 clips that are part of the D1 and B1.