Ideal for wiring up instrument panels.
Crimp tab terminator - for use as a couple with the crimp receptacle. These are often used on something like a PTT or Cruise/Climb wires to make panels removable.
Red receptacles are designed for 22AWG to 16AWG wire.
Blue is designed for 16AWG to 14AWG but is often used with higher gauge (such as 18AWG) for wiring up ground buses for instrument panels.