Sta-Kon RAS18-10X HEATSHR RING TERM, 22-18, No10, RED

The RAS18-10X takes 22 to 18 AWG conductors. That is the small-gauge range you see on control wiring, thermostat and low-voltage runs, and appliance leads. Anything heavier than 18 AWG will not seat in the barrel, so step up to a 16-14 AWG terminal for those conductors. The red insulation is the standard color code for the 22-18 range, which makes it easy to confirm the right terminal on a crowded bench.

It is a No. 10 ring, so it slips over a #10 screw or stud. That covers most terminal blocks, ground lugs and panel studs in control and low-voltage work. For 1/4 inch studs you need a larger ring; the #10 tongue will not pass over one.

Yes. The RAS18-10X carries a 600 V rating, which covers standard commercial branch circuits, control panels and motor control wiring up to that level.

A heat shrink terminal like the RAS18-10X has an insulation sleeve you shrink down over the crimp and onto the wire jacket after crimping. That gives strain relief at the wire entry and seals the barrel against moisture, which a plain vinyl barrel does not do. Use the heat shrink version outdoors, in wash-down areas, pump and marine panels, rooftop equipment, and anywhere vibration works a conductor loose. For a dry interior panel, a standard vinyl insulated ring in the same 22-18 AWG range does the same electrical job.

The conductor barrel and tongue are copper, so it mates properly with copper conductors, which is what 22-18 AWG control and instrumentation wire almost always is. Do not use it on aluminum conductors; those require a terminal rated for aluminum to avoid a dissimilar metal connection.

Two steps. Crimp first with an insulated-terminal crimper set for the 22-18 AWG red range, then apply heat to shrink the sleeve down over the barrel and wire jacket. A heat gun is the right tool; an open flame scorches the sleeve and can leave the seal incomplete. If you only crimp and skip the heat, you lose the moisture seal that is the whole point of the heat shrink version.

Manufacturer part number is RAS18-10X from Sta-Kon. Read it as R (ring), AS18 (adhesive-lined heat shrink, 22-18 AWG, red) and 10 for the #10 stud. If you need the same terminal on a different stud, the trailing number is what changes.