A combo frame commonly found in the Altman R40 (and similar) striplight as a means to hold color media, such as rondel or gels.
A combo frame comes in two pieces, which can be reversed from the thickness required to facilitate a rondel, to the slim form needed to sandwich a standard gel.
While rondels are expensive, heavy, fragile and come in a limited variety of colors, the combo frame allows technicians to use more inexpensive gels, in a broader range of colors. Note that some fixtures, such as the 'A-lamp' striplight (pictured below) have no means to accept a combo frame.
Altman R40 with combo frames holding rondels:
A combo frame comes in two pieces, which can be reversed from the thickness required to facilitate a rondel, to the slim form needed to sandwich a standard gel.
While rondels are expensive, heavy, fragile and come in a limited variety of colors, the combo frame allows technicians to use more inexpensive gels, in a broader range of colors. Note that some fixtures, such as the 'A-lamp' striplight (pictured below) have no means to accept a combo frame.
Altman R40 with combo frames holding rondels: