From the Autodesk App Store...
This tool is designed to weigh the Ducts in the project and extract the weight of each one. This helps the designers to calculate the Duct weight .This enables the users to produce more accurate design.
About This Version
Version 1.0.0, 4/25/2016
The Duct Weight add-in is brought to you by BIM SOFT and is priced at 3.00 USD.