I received this and the M4 set at the same time and I can't tell you how happy I am with these acrylic screws for assembling 3D printed parts. Acrylic sticks easier to my PLA parts but still holds up well. I also find that 3D printed filament isn't perfect and acrylic fittings seem a lot more forgiving. I like that they are almost transparent. Ideal for 3D hobby.