this vendor says it's for 25kgs
https://www.tweekscycles.com/uk/thule-pack-n-pedal-tour-rack-xt-madthp100090/
https://www.tweekscycles.com/uk/thule-pack-n-pedal-tour-rack-xt-madthp100090/
The rack is rated to 25kg load capacity and like all products it is covered by Thule's usual 5 year warranty.