300-Pcs M3/ M4 /M5 Female Thread Brass Knurled Threaded Insert Embedment Nuts Assortment Kit

I like insert very much. Once I figured out the hole to drill, the insert went in perfectly and didn’t spin. Which brings me to my negative comment. Spent a little bit of time finding the rite size hole. They should give some reference to the pilot hole sizes.

the perfect addition for my 3d printer.