Double

Double roller shades – also known as dual roller shades – are a type of window covering that have both light filtering and blackout roller shades installed in the same window frame, which can be used together or separately. Usually, the blackout shade goes in the back (with or without side channels). A solar or light filtering shade goes in front. Most of the time these shades are installed with special dual brackets, which pair nicely with either a 4 or 5 inch fascia or valance. There are also dual brackets for exposed regular and/or reverse rolls, so you can find the right look for your home or office. 

Double roller shades are sometimes called combination shades because the two types of fabric work well independently but are even better when used in combination with each other.