The Polaroid P Series Filter Holder is made out of high impact material, accepts 3” square filters and holds them snugly in place. And extra creativity is made possible with the incorporation of a triple filter track. Two or even three filters can be combines to give you simultaneous effects. A filter holder adapter ring with a thread size matching that of your lens must be used in conjunction with the holder. Includes 1 slot for large round (CPL, ST) filters. Polaroid adapters are sold separately. Note this is a Polaroid branded item.