If you downloaded this from a specific website or forum, refer back to the original post; authors usually list the "Table of Contents" or a manifest of what the full archive contains. Do you have the total number of parts in this set, or
Based on the name "NextCatalog," this file likely belongs to one of the following: NextCatalog.part4.rar
Open the first file ( NextCatalog.part1.rar ) with a utility like WinRAR , 7-Zip , or The Unarchiver . The software will automatically pull data from part4 and the others to reconstruct the original file. If you downloaded this from a specific website