This PHP Script has an Anti-Leech feature turned on.

Make sure you are accessing this file directly from www.steam-brite.com

It seems you are trying to get it from https://steam-brite.com/literature/schematics/index.php?dir=Powrflite%2FSpec+Sheets%2F&file=PF2004-2008.pdf

Your IP address has been logged.
18.222.182.249 (ec2-18-222-182-249.us-east-2.compute.amazonaws.com)

Here is a link to the directory index the file is in:
http://www.steam-brite.com/literature/schematics/index.php?dir=Powrflite/Spec%20Sheets/