Kadrick 420Pcs M3 M4 M5 Threaded Inserts Assortment Kit for 3D Printing Components, Metric Brass Knurled Nuts, Insert by Heat into Plastic Parts

I appreciate the nice selection of sizes and overall quality of these inserts. They work fine for my applications. Install easily using the Kadrick soldering iron tips. Since my application tends to be "one and done" use where the screw is seldom, if ever, removed, I can't comment on durability. I don't see any red flags that make me think these are less durable than any others that I have used. If I have one negative comment, it is that I would like the assortment to include more sizes of M4 and perhaps fewer M3. That said, this provides plenty of selection for prototyping parts and validating design and functionality. If I find that a different length insert in the prototyping stage, that is easy to resolve when I purchase larger quantities for production runs.

Great set of screw inserts for those who are on a budget. All inserts are machined well and screws thread very nicely into the insert. Would recommend to purchase. Set also has a nice variety of inserts as well.

High quality, consistent and accurate dimensions.

Works just as expected and no issues with setting them using a soldering iron. Case is sturdy enough but I'd keep a rubber band around it just incase, would hate to have it accidentally open and try to pick up all the inserts. Only have tried the m5x10 and it worked perfect with my m5 bolt that I used. Great value for the money and good variety to test out. Will refill with the same brand as needed.

A great value and they work well. It's nice to know I've always got a bunch on hand rather than ordering a few for each little project.