Got a 12ga wire running along under a panel in a hard to get to place. With
great efforts and contortions, I can reach it to cut it and strip insulation
of the cut ends.

What I need to do is rejoin the cut ends, and come off with an additional
wire to go to a different location.

If there's slack, I can put the three ends together and use a wire nut.

Assuming there isn't enough slack for the wire nut trick, are there any neat
little critters out there for this specific purpose? What are they called?
Who has 'em?