Bones SPF 84B P5 Sidecut 'Circle Skulls' Wheels

About Skate Park Formula™ (SPF) Skatepark Formula™ (SPF) is very high quality urethane specifically formulated to resist flatspotting on slick or smooth surfaces while maintaining a higher rebound for a quicker response and a faster roll. Skatepark Formula™ has a high resistance to abrasion while not compromising hardness and slide ability. Simply put… Skatepark Formula wheels grip better on slick surfaces, are almost impossible to flatspot, and are the fastest, longest lasting wheel on the market today. You won’t find our Skatepark Formula from any other wheel supplier so get a set and find out for yourself what the word on SPF is all about. About DUROMETER B SCALE Shore Durometer A Scale is good, but it does not cover the entire range of skate wheel hardness and is very limited because the scale goes from 1 to 100 and anything over A 95A does not compute accurately. Shore Durometer B Scale is perfect for skate wheels because: It is very similar to the A Scale, but reads 20 points