I build decks in the summer, as my profession is a school woodshop teacher. This kit is the correct size for all the 'new' quick hardware mounting bolts and fasteners. Works for the screws for joist hangers, the bolts for posts, and the ledger fastening bolts as well. First let me say that I have run more than 500 ledger bolts into the Rim of the house, and the runner has never stripped, fallen off, or failed at all. I use my 885 impact driver and they sink in crazy fast. Second, the magnet holds 8 in or longer bolts in as I hold with 1 hand and line up the bolt and impact gun with the other when setting posts. I did not think a set of nut drivers would make the work on setting bolts and other fasteners in deck construction so much easier, but they have. The other brands, for whatever crazy reason, if a worker would mistakenly run the bolt before ensuring the nut driver was all the way over the bolt, that driver would be shot for the next person. This set has stood the test of time, and barely looks used!! Solid Buy