In many developer circles, "17.58" refers to a versioning timestamp (e.g., Year 2017, Week 58) or a specific build sequence.
The .7z extension indicates the file was created using 7-Zip's LZMA algorithm , which offers a much higher compression ratio than standard ZIP files. 17.58.7z
Download the 17.58.7z file and extract the contents using 7-Zip or WinRAR. In many developer circles, "17