Sta-Kon RB14-250FP INS NYL PIGGY BCK 250 DISC No16-14, 100 Pack

A piggyback disconnect is a female .250 quick-disconnect with a male tab built into the back, so you can land one wire on a terminal and plug a second connector onto the back of the first. That is how you feed two circuits off a single spade terminal on a thermostat, relay, blower motor, or appliance switch without doubling up wires under one screw. The RB14-250FP takes No. 16-14 AWG wire.

It is sized for No. 16 through 14 AWG stranded wire. If you are terminating 22-18 AWG, this barrel is too large to crimp reliably and you need the smaller gauge range instead; 12-10 AWG will not enter the barrel at all.

Yes. It is a 250 series disconnect, meaning the receptacle mates with a .250 inch (1/4 inch) wide male tab, which is the common tab size on HVAC blower motors, contactors, and appliance switches. The integral male tab on the back is the same .250 size, so a second 250 female disconnect pushes onto it.

The blue sleeve is both. Blue is the standard color code for 16-14 AWG insulated terminals, so a tech can identify the gauge range at a glance, and the sleeve itself is nylon/polyamide rather than vinyl. Nylon takes more abuse during installation and resists cracking better than vinyl when the terminal is flexed or pulled off a tab repeatedly.

It carries UL file E66716. That is the citation to give an inspector or include in a submittal package when control-panel or appliance wiring terminations have to be listed components.

That is exactly the case for it. Where a device only has one spade tab but two loads need power, the piggyback lets you stack a second standard 250 female disconnect on the back instead of cutting in a wire nut or adding a terminal block. Where you have more than two conductors to land, or the device tab is a different width than .250, go with a terminal strip or the matching size disconnect instead.

Brass. Brass barrels and receptacles are what you want for repeated plug and unplug cycles on control wiring, since the spring contact holds tension better than a soft copper sleeve. It also means the crimp should be made with a tool matched to insulated 16-14 terminals, not a bare-terminal die.

Order it as Sta-Kon RB14-250FP. The RB prefix is the insulated piggyback body, 14 points to the 16-14 AWG range, and 250 is the .250 inch tab size. It is sold in a 100 pack, which is the quantity most panel builders and HVAC service trucks stock it in.