While most of the newer style rivnut setter tools are used parallel to the insert nut, there are places where a right angle tool is necessary.This is a good tool for smaller inserts up to 1/4-20 when you have limited room and can use a right angle tool. It will set rivnuts best if you do not try to set them in one crimp stroke.This comes with 9 mandrel sets, including both 5mm and 10-32 which is redundant in almost all circumstances since 10-32 and 5mm x0.8mm are virtually alike (0.8mm = 31.75 TPI) But it is still nice to have what amounts to having a space mandrel and more inserts. Since I use 10-32 stainless steel screws most often, this is an advantage.I have been using rivnut setters for over 30 years. I was recently looking for the nose and mandrel sets for those earlier rivet gun looking types. (Harbor Freight still sells a few models, such as SKU 1210 or 94100) I couldn't find those mandrels easily anymore. So a few months ago, I bought a Doyle 10" parallel type, like the design of the head better than the earlier type of head. The Doyle uses the mandrels and heads like this vendor sells. This type of mandrel and nose piece is easier to change and adjust than the old type.So I followed up by buying this AIUITIO 8" Rivet Nut Tool for perpendicular installation and a longer RZX 16" RIVET NUT TOOL for more leverage when there is room to work. All those tools, and any others that come with the mandrel/nose piece in the little rectangular plastic boxes like these do will work. I did find differences in the quality of machining on the different tools, but all worked fine within the range of rivet nuts sizes they are supposed to install.The Doyle had the best machining of the business parts of the tool. This AIUITIO 8" tool was next best in this regard. The RZX 16 inch tool had rougher machining than the other two. This is only really noticeable in an important way when threading the mandrels into the head of the tool.However, all three tools are competent as long as you don't apply too much torque. Too much torque can break a mandrel on the smaller mandrels. It also just makes the job more difficult. DO not operate any of these tools with the handles open farther than is easily comfortable and crimp in two actions, adjusting the tool in between compressions.The mandrels that come with this kit are machined well and easy to install. Just don't count on the directions to be of any use. That goes for the other two crimp tools. The directions are written with the same poor translations as many Japanese products had back in the 1960's. The instructions say there is a step drill in the kit. The supplier dropped that from the kit some time ago, as others have pointed out. I don't recommend using a step drill to drill the holes in sheet metal as it is too easy to over-drill. Drill a hole to the measured size of the shank of the insert for best results.This toll comes with a fitted plastic case that holds eight mandrel sets in their boxes along with the crimper on one side. On the reverse, there is another set of bins for extra mandrels, the adjustment wrench, and fasteners.The one criticism I have is one I have read about other kits and sometimes the bulk inserts. The bags of inserts that come with the kit are not resealable. When you open them, you have loose inserts that you have to put in a bag or container. I will note that the bags of insert nuts in this kit are very well marked.As a comparison, the fasteners that came with the Doyle tool are also not resealable, but the 16 inch RZX tool came in small zip lock type bags.I have no idea of long term durability, but since the tool I have been using for over 30 years is still in good shape and is of lower strength of materials than this AIUITIO branded tool, I think it will last a long time.All in all, this is a good kit at a good price, but it is not the only good choice.