Smooth - Smooth wheels come with a shiny coating on the riding surface that feels grippy at first, but wears away quickly.
Medium - Your classic wheel shape, versatile all-around wheel for street/park skating.
Skatepark Formula (SPF) - Twice-baked for faster speed and high resistance to flatspots. Excellent grip and release control.
84b (104a) - Hardest, fastest wheels designed for advanced (pro level) skateboarding.
The 'b' scale measurement reads 20 points lower than the 'a' scale: 84b would equal a theoretical hardness rating of 104a.
Made in the USA - Poured in Santa Barbara, California.