I made several hundred connections using this type of connector at my previous job as a field engineer at AT&T. Connecting wires with butt connectors provided to me by AT&T has very, very rarely failed. These fake 3M Scocthlok connectors looked exactly like the ones I've used in the past with great success, but that's the only thing they had in common. When I opened the package I saw that several connectors had come loose. Several "buttons" used to crimp the splice have come loose from the piece where the wires are inserted. So 10% or so was useless to begin with. The first connection I tried to make with these connectors failed because the metal pins used for the jumper were not fully embedded in the wires. The same error occurred a few more times before the pins successfully dug into the wire insulation and held it in place. For those who don't know, once the butt joint is crimped it cannot be broken. Previously, between those that fell apart in transit and those that couldn't make connections, twenty of these inferior connectors were wasted before two solid 24AWG wires were successfully spliced together. This pattern of multiple failures before a connection was made was repeated over and over again. 1 out of 6 of these poor quality connectors worked. In addition to using inferior material and poor workmanship, these butt joints contained very little, if any, hydrophobic gel to protect the bare metal at the joint from corrosion. Therefore, any external connection made with these connectors will fail in a year or two. I deeply regret buying these plugs despite being so cheap. But if only 10 out of 50 connections work, it's not worth the money saved, especially when the frustration of each failed connection turns a simple chore into a nightmare!