Seismic - Mango 54mm x 81A Oscar Wheels (4 pack) - Longboard Wheels54mm tall x 33mm wide 18mm running surface Centerset bearing seat 2. 41 oz. each Seismics new All Terrain street wheel, in the worlds fastest thane. Roll faster, smoother, and more comfortably over inconsistent or rough pavement. A breakthrough Filmer wheel, too: Roll further with each push, making shots smooth as silk! Poured in Seismics proprietary DEFCON the urethane behind the World Speed Records for both Skateboard (91MPH) and Street Luge