My son has a Mini -Bike and many parts are attached with hex bolts including the brake assembly, brake disc, rear sprocket and fenders.I also work on machines with small gas engines such as pressure washers, mowers and chainsaws.All of these machines use hex bolts to hold them together and this bit set pays for itself every time I have to work with it. That. Fast. Jobs that used to take minutes to hours to disassemble and reassemble now take a fraction of that time. I can do a chainsaw in minutes with just one battery -Impact wrenches and them (and a set of 1/4" metric sockets for disassemble the locking adapter). Contains SAE and metric bits in a compact plastic case. that fit comfortably in the carrying case of my impact wrench. I highly recommend them for the price and durability. I haven't disassembled any of them yet and have come across some pretty stubborn screws.