The RZ Mask F1 Mask Filter is a 3-pack of medium-sized filters in gray. It features an active carbon element for filtration. The manufacturer's part number is F1FILTER8282828, with an alternative MPN of 2503-0484. It is a unisex accessory with a warranty of 90 days and free shipping to the lower 48 states. The product is designed for use in a filtration face mask.