Look for silicone tubing that’s 6mm id, 8mm od. That one you linked is 10mm od. That’ll be mucho work to size down to 8.5mm
Something like this could work
uxcell® 6mm x 8mm Translucent Silicone Tube Water Heat Resistant Hose Pipe 2 Meters Length
https://www.amazon.ca/dp/B01N63VBMX/..._Eq50AbKV0BNED