Not sure exactly, they're fairly chunky but the quick clip on the pannier fits but the rack is a bit short and missing a central support for the anti sway clip on the back of the bag.
Have a look at the burley coho xc qr panniers, they utilise a top slide bar for the qr clips and one for the bottom attachment.
Also rhinowalk brand (china) have the same set up, I have a pair for my thule rack on my roadrat and the panniers are 30l each if it's not raining, other wise 25l each.