TC-G is ideal for composites and hardwoods 1-1/4" to 2" in harsh or coastal environments. Use with pregrooved boards or cut groove with router or biscuit cutter. Controlled, uniform 3/16" spacing.Superior holding power. Black coating for decreased visibility. Quick & easy installation. No glue or special tools needed. All installation done from the top. One bag covers aprox. 50 sq.ft. Installation videos and instructions available at www.deckfastener.com