I bought these instead of the cheaper ones because I have confidence that US made drills will fit. The seven different ones I used were measured by the wire sizes they were connected to. The racks for the brackets in the metal box are also made of metal and are separated from each other so that you can easily read the dimensions. A good buy.
Okay, a little I'm a little crazy about tools. I have 5 drill safes of different types. I try to buy better ones. This good. I admit that I mostly use it with wood so I can't say it's impressive. But I have a couple of drill presses and I use them in them and in metal. They work fine. I use a drill primarily to sharpen bits and I have to say I don't do much with it.
I tried this item with no prior reviews and it worked great. Each of the 60 bits measures +0.000 to -0.001 inches, nice sharp grooves and clear laser engraved marks. The metal body is very compact and each nozzle is marked with inch diameter, wire gauge number and corresponding tap size where applicable. This set is as premium as the price suggests ($64.13 + Prime as of August 23, 2013).