These springs are exactly what I needed. I contacted several places looking for torsion springs that measured .25 in diameter, only to be told there was no way to get that size springs. Then I found Andy at Bladeops. He asked me to send a picture of the knife I needed the spring for. I laid the knife with the blade open next to a ruler and Andy did the rest. I did order extra springs just in case it becomes difficult to get more in the future. Andy was a true professional and the springs are exactly the proper fit for a knife that requires a 1/4 (.25) diameter spring.