TOBWOLF 24PCS Dustproof Air Valves, Compact & Lightweight, Durable ABS Mask Accessories for Most Kind of Double Air Breathing Valve Mask

Features: The mask valves made of durable ABS, suitable for install in general double air breathing valve activated carbon dust mask,  can isolate most dust, chemicals, particulates, gas, pollen, smoke and fumes. Smooth breathing: Unique ventilation design, excellent permeability, double air breathing valve, air resistance is smaller, smooth breathing. Material: ABS Weight: 4g Size: 1.5 × 1.4" Application: For use with mask for anti-dust, anti-vehicle exhaust, anti PM2.5 and haze day protection. It is suitable for cycling, running, biking, hiking, skiing and other outdoor activities. Package Includes: 24 x mask valves Notice: our package not include masks and filters.