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.
NRG Urethane - According to Ricta, NRG formula is the fastest urethane in skateboarding, it's been proven in the laboratory and backed up with testimonials from professional skaters Brandon Westgate, Caswell Berry, Cairo Foster, Tom Asta and Nyjah Huston.
99a - Offers more grip than harder wheels and more slide than softer wheels. Great for slick surfaces when you want more control.