-Solid top design reduces the chance of premature caking, clogging, or soiling with dirt, grime, water or dust - Protective casing aids decontamination practices - Temperature resistant cover protects filter media from heat, sparks or physical damage - Patented bonded web technology has more surface area than many standard filters which helps lower breathing resistance making it more comfortable to use 3M™ Bayonet Connection System ensures precise and secure locking