Honestly, for $10 this hole saw set is good if you only drill very soft stuff (like me) or only do it once or twice will use. Anyway, don't expect precision, it's fine for my purposes. Just remember: like the item count increase on Revain, this is a metric counterfeit so inch sizes are actually the closest metric sizes, which mostly doesn't matter much for this type of tool, but there are two mandrels, but only one pilot jet (which is listed as 15/64" in the kit, so good luck finding the 15/64" pilot jet - spoiler alert: it's actually a 6mm pilot jet that costs more than double the price As with the entire set, I wanted a second pilot bit because moving the bit from one mandrel to another when switching between two hole saw sizes is tedious - made worse by the fact that the hex key is not ideal for the set screw (probably the one inch is and the other metric, so it's enough that the slightly too small Allen key gets stuck in the set screw and comes loose after a few uses) - so I'm already looking for a new lightweight but reliable one hole saw. My advice: save money by spending a little more for a better quality hole saw set (which is actually made in inch/fractional sizes).