3M PPS Lid & Liner Kits (first version - not compatible with 3M PPS Series 2.0 items) each contain disposable lids with welded-in filters to strain paint material while spraying, along with liners and sealing plugs for use with the 3M PPS Paint Preparation System. Kits are available in four sizes for a range of jobs from large to small. 3M PPS Paint Preparation System is a complete painting system that allows the painter to measure, mix, filter and spray paint materials.