3M™ Secure Click™ Hard Case P100 Particulate Filter D9093C, Hydrogen Fluoride and Nuis. Level OV/AG Relief, 60 ea/Case. 99.97% filter efficiency meets NIOSH P100 test criteria. Use with 3M™ Secure Click™ Respirators. Hard case recommended for harsh environments with a need for easy decontamination and protection. Hard case helps protect against sparks and high heat.