Y connector is using to increase the cables in duct.For example If there are 1 cables in duct you can increase it to 2 or you can
increase 2 cables to 3 cables.
If you do not use this tool you can not increase cables because you can not prevent air leaks without this tool.
You can use this tool for different ducts and cables by using parts which we give with tool.
We need to learn your ducts and cables diameters to product this device.