Check the listing for details. GRAINGER APPROVED SBM-4FG Dust Plug,Type DP,Polypropylene,4" 6YZF5. Condition: New. Listed at 127.43 USD. Dust Plug, Plug, For Coupling Size 4 in, Body Material Glass Filled Polypropylene, Type DP, Coupling Size 4 in, Natural, Overall Length 5 in, Includes Locking Arm No, Plug Length 5 in Type DP food-grade polypropylene cam and groove dust plugs plug into Type B, C, and D female couplers to seal the end of the connection. Dust plugs seal leaks and prevent debris or other materials from entering the connection. Food-grade polypropylene (also called PP) is a white thermoplastic material that resists UV, weathering, and ozone damage. Food-grade polypropylene dust plugs are used for food and beverage processing, pharmaceutical production, and medical applications.Polypropylene cam and groove fittings consist of a grooved male nipple (adapter) and a female cam (coupler or camlock) that tighten tog.