Bosch is an original equipment global leader in mass air flow technology. Bosch Mass Air Flow (MAF) sensors ensure low levels of harmful emissions with greater fuel efficiency and improved engine performance. Bosch units come packaged as a complete unit. The sensing elements are paired and calibrated with the housings on the production line to ensure precise operation. Some competitors offer a simple sensing unit replacement as opposed to a complete unit. In such cases if the failure is not in the sensing unit itself, the repair may not be corrected the first time. This can cost the consumer or technician valuable time & money.