This AiO is for the RTX 3080/3090 in reference design and will not fit your 1080ti. To find a suitable watercooling for your 1080ti, the exact product designation is required (e.g. ASUS GTX 1080TI Strix OC), as each watercooling block is produced individually for certain cards/manufacturers (board design).
As an aid, you can use this configurator to find suitable water cooling solutions:
https://www.hwconfig.com/waterblock...
Hope I could help :)