Just like every other barrel combination lock, these are trivial to compromise. For me, trivial equals not needing any tools and opening it quickly enough to not draw any attention in a public space. Recently someone locked their bike to my fence with one so I figured it was fair game since it was on my property & fastened to my fence. The combination was "FUSE." The first thing that popped into my head was "short fuse" so I put the lock back on and spun the tumblers.
Doesn't matter, had bolt cutters. While it's easy to open most of these combination locks, it's always faster just cutting through it. So two locks won't help at all if one takes under five seconds to get through. One proper lock that can't be cut with smaller cutters and a hope is all you need. Hope that someone with a bigger cutter, pneumatic one, or an angle grinder won't come/
