We have 3 styles of wire connectors. The winged wire connector style is great because at the bottom of connector there are flaps to allow you to get the leverage needed to twist the wire connector. The easy cap twist connectors have the flaps at the top.The barreled connector a little more inexpensive but still does the job.All connectors are UL94V-2 flame retardent and have a fixed square wiring spring which grabs wires tightly.