6 awg is the wire guage. thhn is the insulation type as is thwn-2. This wire is copper and needs to be placed in a raceway/conduit between termination points.. the insulation rating thwn-2 allows the wire to be in a wet location inside conduit. One word of caution do not use the 90C ampacity rating only 75C or 60C.
A forum community dedicated to Do it yourself-ers and home improvement enthusiasts. Come join the discussion about tools, projects, builds, styles, scales, reviews, accessories, classifieds, and more! Helping You to Do It Yourself!