Review on Wago Lever Nut 221 415 Conductor Connectors by Stephen Cernatescu

Excellent product - I don't know how I used to live without these things for use in electrical junction boxes. It's not very painful to twist multiple wires in a cable cap (I have carpal tunnel), they have two probe test terminals, and you can use them to form circuits literally as fast as you can strip wires in a junction box. They are simply better in every respect than even connectors from Wago or Ideal. You can use them with wire sizes from #20 to #12, both solid and stranded. They also sell a higher amperage version (221-615) rated at 30 amps that supports #10 wire. The only downside is the cost as they are obviously significantly more expensive than standard mass produced wire caps. However, the cost is quickly offset by the reduction in the labor cost of installing them - as far as I understand this offsets the extra cost. Also, you never have to worry about a bad connection or broken cable due to a badly twisted cable end.