Wide - More traction and stability at high speed so you'll be less likely to slip out of your line.
Smooth - Smooth wheels come with a shiny coating on the riding surface that feels grippy at first, but wears away quickly.
Skatepark Formula (SPF) - Twice-baked for faster speed and high resistance to flatspots. Excellent grip and release control.
81b (101a) - Most common durometer offering a good balance between speed and grip. Meant for skateparks and other smooth surfaces.
The 'b' scale measurement reads 20 points lower than the 'a' scale: 81b would equal a theoretical hardness rating of 101a.
Made in the USA - Poured in Santa Barbara, California.