Everbilt 3 in. to 4 in. Plastic Duct to Duct Increaser

The Duct to Duct Increaser connects 3 in. to 4 in. ducts together. It is ideal for bathroom fan exhaust applications. Finished in black color. The increaser is designed to be a tight fit to reduce air leaks in the connections. When using the increaser with a 3 in or 4 in snap pipe (aluminum or galvanized) , it may be necessary to unsnap the receiving end of the pipe, then insert the increaser and snap the pipe back together.