FileInfo.com - The File Extensions Resource

.B5T File Extension

File Type	BlindWrite 5 Disk Track Information
File Format	File
Common?	No
File Description	Contains descriptor information for a disk created by BlindWrite; typically saved with a corresponding .B5I file; relatively small compared to the .B5I file
Program(s) that open b5t files	Windows: VSO-Software BlindWrite; IsoBuster; EZB Systems Ultra ISO

Information from FileInfo.com - The File Extensions Resource.
http://www.fileinfo.com/extension/b5t