michaelgroves
Explorer
Having said that, their Achilles heel is that they are both metric and Imperial, so they don't fit aas well as they should. This has 3 snags:
1) The sockets are physically bigger than they need to be - not good for confined spaces.
2) There is more movement required when ratcheting back and forth, due to the extra play - also not good for confined spaces!
3) They are more likely to round a bolt-head/nut than they would if they were a perfect fit.
I should clarify that the first problem - the larger size of the sockets - is not entirely due to the dual metric/imperial fit. All flank-drive sockets and spanners will be slightly bigger in diameter than an equivalent conventional 6- or 12-point socket/spanner. (This is to accommodate the bulges that press on the bolt-head flats).