Sta-Kon RAA21M INSUL NYL BUTT SPLICE 22-18 MYLAR

The RAA21M is sized for 22 to 18 AWG stranded wire on both ends. Anything heavier than 18 AWG will not seat in the barrel, and a 16 AWG conductor forced in will crack the nylon sleeve or crimp off-center. For a low-voltage thermostat, control, or signal run in that 22-18 range it is the correct size.

Yes, it carries UL file E9809. That is the detail an institutional or MRO inspector asks for when splices are going into a controls cabinet or equipment build that has to pass a listing review.

Use an insulated-terminal crimper with a red (22-18 AWG) nest, which matches the splice's gauge range. The barrel is crimped once on each side, one conductor per end. Pliers or a cutter's crimp notch will flatten the nylon sleeve without forming the barrel properly, and the connection pulls apart. No tool is supplied with the splice.

Red is the standard gauge color code for 22-18 AWG terminals and splices, and the RAA21M follows it. If you are working in a panel and need to confirm at a glance that a splice matches the conductor, red means 22-18. Blue bodies are 16-14 and yellow are 12-10.

The RAA21M uses a nylon insulating sleeve rather than vinyl. Nylon is the tougher of the two, so it holds up better when the splice is pulled through a raceway or flexed in a wiring harness, and it resists scuffing during installation. Vinyl insulation is softer and more easily nicked. Both make the same mechanical crimp on the conductor, so the choice is about how rough the handling and routing will be.

Yes. Both barrel ends of this splice are rated 22-18 AWG, so a 22 AWG conductor on one side and an 18 AWG on the other both fall inside the range. Crimp each end separately in the red die. If either conductor is outside 22-18, use the splice that matches that gauge instead.

A butt splice like the RAA21M makes an in-line, low-profile crimped joint between two conductors, so it is what you want inside a harness, a conduit run, or anywhere the splice has to pass through a tight space and stay put. A wire nut needs a junction box and room to fold the conductors back. A terminal block is for connections you expect to open again for service. For a permanent 22-18 AWG in-line repair, the crimped splice is the one.

Country of origin is the United States. That matters on government, federal facility, and some institutional contracts that carry domestic sourcing requirements on electrical components.