Bones Wheels 81B SPF Circle Skulls P5 Sidecut

Skatepark Formula™ (SPF) is a high-quality urethane specifically designed to prevent flatspotting on smooth surfaces while providing a higher rebound for faster response and rolling. Skatepark Formula™ has high abrasion resistance without compromising hardness and glide. Simply put, Skatepark Formula wheels grip better on smooth surfaces, have minimal flatspots, and are the fastest and most durable wheels on the market. You won't find our Skatepark Formula anywhere else, so grab a set and discover what SPF is all about for yourself.