At last Sims \"Street Snake\", the wheel for quad rollerboots of the 1980s and 1990s, have been re-made...no longer do you have to pay £££s for a crappy used set, or get a mortgage for some NOS ones you'll never dare to use. They now have a slightly different design with a much improve core but are basically the same wheels you rode in the 1980s.The core is tough nylon to hold the bearings perfectly aligned while the high rebound polyurethane is free to flex & perform as it should. They are very grippy, smooth, fast, long lasting and silent...what more do you want! Ideal for both indoor and outdoor use - they grip really well on slippery rinks & outside they roll over rough surfaces with ease.Perfect for Roller Derby skaters as an outdoor training wheel. They will fit all makes of Derby skates using the same bearings as already in your indoor wheels. 62mm diameter 34mm wide tough nylon core 78a hardness Flat back edge large radiused outer edge Take 8mm wide spacers