I ordered these for auto work which I have put aside until I have decent quick couplers (these). The quality of the plastic on it is surprisingly low, almost half of all the crimps I've made resulted in the entire plastic shell detaching and falling apart, forcing me to cut off the connector and start over. I have never experienced such poor quality. and threw away the remaining pieces (probably over 150) just so I don't forget them and use them again in the future and rely on them. I made a "Hilitchi" list on Amazon to warn me to stay away from this brand in the future.