Blast gates are used to open and close branch ducts to divert airflow only to those machines in operation. This conserves air volume and keeps suction strongest where dust is being produced, thus maximizing dust extraction. These ABS plastic blast gates are very economically priced to allow you to outfit your dust collection system for maximum performance. These fittings are abrasion resistant and are designed to withstand the abrasive nature of wood chips and saw dust. Due to the potential for built up of static electricity, it is recommended that all dust collection systems with plastic fittings be properly grounded.