The operatable word is virtual
I installed this packing 3 years ago. It does run dripless, but it also requires occasional adjustment. So it really does drip some until you take a half-turn or so. For most of the season, I get "virtually" no water. Then for unexplained reasons it may start to drip and will require an adjustment.I would use it again (and I plan to) because I think it is better than conventional packing.Perfect? No.