I used these instead of screw couplers because I felt they would hold the EMT tighter and tighter. They are made from durable solid steel and work well when tightened with a crescent wrench. On the inside it has a stop in the middle to allow the EMT to slide. I deducted a star because the connected tubes are not perfectly straight after compression and can move a bit because they are not straight. However, I would still use them over die cast screw couplers instead of those good strong steel couplers.