For use in wet or dry locations, THHN building wire is 19-strand 600-V uncoated copper, available in 4-14-gauge sizes.
The 19 and 26-strand, 600-V bare MTW-type wire, for use in control cabinets, machine-tool applications, and appliance-wiring applications, is available in 19 and 26-strand 600-V bare, annealed copper in 10 to 16 gauge sizes.
TFFN-type wire, available as 16-gauge, 26-strand, 600-V uncoated copper, is used as fixture wire in dry locations. All wire types are color-coded with tough polyamide, nylon outer covers.
AutomationDirect, 3505 Hutchinson Rd., Cumming, GA 30040, (800) 633-0405, automationdirect.com