Built into a single-stage self-contained unit, the Rota Pola Rota-Tray 4 x 5.65" with Circular Polarizer from Revar Cine is a compact, easily rotatable polarizing solution for most matte boxes that accept 4 x 5.65" filters. Rather than requiring a full 4 x 5.65" glass filter, the Rota-Tray uses an included 138mm diameter filter which sits inside the rotating tray. If the polarizer needs to be adjusted, simply rotate one of the geared wheels, which extend from the top of the tray on either side.