Variable-speed airflow to keep you continually comfortable. The variable-speed blower motor in the SLO185V lets it adjust the speed of its airflow, so it can disperse even heat throughout your home. Better airflow control also means a better balance of temperature and humidity. The SLO185V is made with a Beckett® burner. This means extremely efficient combustion for greater fuel economy all winter long. It also means the burner is unaffected by drafts or poor chimney conditions.