Rather than downloading a potentially unsafe compressed file (like a .rar), ASHRAE provides several official, secure methods to access this data:
Searching for a ".rar" version of this database often leads to unofficial file-sharing sites. Be aware of the following: Duct Fitting Database - ASHRAE Download ASHRAE Duct Fitting Database rar
A more comprehensive mobile version covers all 240+ fittings listed in the ASHRAE Handbook of Fundamentals and allows for project saving and report emailing. Rather than downloading a potentially unsafe compressed file