sebo,Sebo....but not one of those twistey ones..lol
Sebo are great for prevac on Carpet Cleaning but are next to useless for more general work due to the design and the way the bag sits on top of the vacuum, 20% full requires a change of bag.
Numatic NRV will fill a bag 100% full as the vacuum is positioned on top and so over the bag. Truly impressive design as the debris weighs the bag to the bottom keeping the vac free and clear at the top. I have even used one cleaning leaves, rubble, sand and grit from a large patio on an Autumn day, several days after clearing prior to repointing and couldn't believe just how full the bag was without loosing any noticable loss of suction, twas the change of tone that told me to change the bag