These 3 way "Y" connectors allow branching of dust collection to add every machine in the shop. "Y" fittings are prefect when space is limited and they will maximize air flow. Must be used with hose clamps of quick connect/disconnect fittings. Overall length is 10" and width is 8". Nominal dimensions: OD of openings are 3 15/16" and ID are 3 11/16". These ABS plastic connectors are very economically priced to allow you to outfit your dust collection system for maximum performance. These fittings are made from 1/8" thick ABS abrasion resistant plastic 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.