The Litepanels 1/2 CTB 1x1' Gel is designed especially for the Litepanels 1x1 LED 3200°K fixture. A full CTB gel will make the light mimic daylight. Sometimes, you may want the light to be somewhat "warmer" than daylight, with less blue in it, so the gels are also available in fractions--this 1/2 CTB gel changes the color of the 1x1 3200°K fixture to 4300°K--more bluish than the unfiltered light. The 1x1' gel is designed to slide into the front of the fixture. Full, 1/4, and 1/8 CTB gels are available separately.