This is only a modification for a TDP Custom tune. You must have already purchased and received a TDP Custom Tune for your Hydra chip. This is to make adjustments to the previously purchased TDP Custom Tune.
Custom tunes built for your 7.3 truck. You must have a PHP Hydra Chip to load these on.
3 tunes for your 7.3 truck. Tunes are for the PHP Hydra Chip. You must own the chip already.