### Question
What does retrofit technology mean?


### Answer
**Retrofit technology** has the following meaning in *42 U.S.C. § 16091a*:

> a particulate filter or other emissions control equipment that is verified or certified by the Administrator or the California Air Resources Board as an effective emission reduction technology when installed on an existing school bus

#### Citation:
  - *42 U.S.C. § 16091a*
  - Heading: **CHAPTER 149-ENERGY POLICY, 2005 > SUBCHAPTER VII-VEHICLES AND FUELS > Part C-Clean School Buses**

