All GBC downloads are free. There is no charge of any kind.
All files are in MP3 format. Most sermon files are about 40 minutes long.
MP3 files are big. If you are on a dial-up connection, a 40 minute sermon could take 40 minutes to download.
Right-click on the hyper linked file name and chose between "Open" (listening) and "Save Target As..." (saving) the file.
Some computers allow you to listen while you download; some make you wait till the download is complete.