mouse.....they are good.mine have been fully loaded to francex2 spain/maroc/lakes x multi etc.not used the extenders (once i think) as i travel lite.came thru a 2 hour thunderstorm in central france (august) believe me it rained!...no leaks. quiet robust.inner bags?....i got 2 bags from kathys (
www.chainspeed) £110 a pair.fully zipped AND expandable to the bmw pannier size!...hit the digs,open,out with 2 bags,off you go.............def buy (both) for me.....
ps...don't use top box.i have a 40ltr waterproof rollbag (ortleib)on my backseat/panniers,bungee'd..also bombproof....days out,2 mins,panniers off......get naked...