It was an advanced holoprojector that was capable of overlaying a stored image on a person or item. It was also known as a holoshroud.
The CQ-3.9x was designed for the entertainment industry and in military simulations. It used a CP-3.3 hologram projector, and incorporated many advancements in hologram technology. However, the CQ-3.9x contained no recording apparatus, and required a CX-3.1 hologram recorder to scan the image of a person or object.
The CQ-3.9x was small and usually worn on a belt. It only had enough memory for one image, and the battery life was only 2 minutes. The image projected had to be at least the same size as the wearer, but was highly detailed and moved with the object or person covered. It was hard for human eyes to detect the hologram, but droids and other electronic eyes could see a flicker that would alert them.