3M PPS Cup & Collar is a hard plastic cup that provides support for the flexible liners. Unlike conventional paint cup systems, the PPS system eliminates the need for mixing paint in additional paint mix cups and transferring the paint through a separate filter. The cup and collar are simple and easy to use. Place the disposable liner within the reusable PPS Cup, mix the paint in the disposable liner, snap the disposable lid in place and attach the locking collar to complete the PPS System. With these simple steps you are ready to start spraying.