@hilde45
The phrase "internal bi-wire" refers to having the four bi-wire conductors (HF/MF pos and neg, and LF pos and neg) encased in one cable compared to bi-wiring using two separate cables that each have a single positive and negative conductor, in which case you would need two of those cables to bi-wire a speaker with four binding posts.
Each HT Pro 9 series cable has four internal conductors, each with multiple, individually insulated wires. The Pro 9 series also uses multiple wire gauges and a different aggregate gauge for two of the internal conductors compared to the other two. The two smaller conductors are for the HF/MF posts and the larger conductors for the LF posts when the cable is used internally bi-wired. The Pro-9 series cables can also have two of the four conductors connected together at both ends, with a single pair of connectors at each end. That is how mine are configured and so I use two independent Pro-9+ cables to bi-wire my speakers rather than a single cable that is internally bi-wired. The Pro-9 series cables are the same whether used as a single-wired cable or internally bi-wired with the only difference being the number of terminations at the speaker end. You could purchase the cable you linked and re-terminate the speaker end with two connectors (instead of four) and they would work great for your speakers.