I have a set of Axiom bags with the "Vario" system. Those hooks alone are not locking but they are adjustable for a snug fit. A middle tab is included that rotates under the rack rail to lock the bags in place. The twist hooks would work better as an add-on if you can find them at Velo-Fred or those from Lone Peak. That said, if you ordered the Vario hooks it would likely include the center locking tab...