Perm A Steel
Multiple layers of expanded Galvanized Steel, enclosed in a medium weight Galvanized Steel frame. Designed as a less expensive option for air applications such as make up air roof top units in industrial, commercial, restaurants, schools, and office buildings where a washable filter is recommended. They can also be used as pre filters, which would remove large particles that easily clog a filter. Pre filters keep the main filter lasting longer and the unit running more smoothly.