This 3M electrostatic pleated air filter is a versatile product that will purify the air you breathe every day. It was conceived to attract and catch debris, lint, household dust, and pollen for a cleaner and better air. It has a MPR of 300. This model measures 20 in. x 20 in. x 1 in and was designed for residential use. Furthermore, it outperforms non-electrostatic filters. Each box contains 6 filters that lasts 3 months each.