CLASS 2 BASE (Artificial Turf Term) Suggest a termBase that has been certified to have the correct ratio of the various sized particles. U.S. Sieve No.Percent Passing by Weight2”1001 1/2”90¾”70 -903/8”60 -70# 430– 60# 875 – 80# 3012 – 50# 200 to0 – 8