Idler pulley tensioner bolt: 16mm

Rotate clockwise

Mounting bolts: T45

My replacement belt was a Continental 6K1130 but yours may vary depending on your vehicle’s package (SE, Sport, R, etc). Mine is the 2017 GTI SE.

Safest bet is to check the numbers on your OE belt.

Belt and tensioner both purchased from Rockauto.com

Helpful video for belt removal from DAP:    • How to Check and Replace a MK7 GTI Belt