Review on GPEH Solderless Through Splice Connector by David Elam

Through wire is very difficult to insert as the elbow does not swivel so you have to wedge the clamp to get the wire into the groove. There were also issues with the metal blade having to cut into the insulation so the contact simply bent instead. Save yourself some headaches and find articulated ones (so they open easily for inserting a through-wire). It's not worth the few bucks saved on these cheap devices.