Sold as a set of 4 wheels
Ricta Chrome Clouds have a wide variety of sizes and hardness to cover the range of surfaces and styles of skateboarding that exist. Chrome Clouds take the Clouds and adds a solid center set core to it. Giving the wheel's urethane more support resulting in a slightly better roll speed. You wouldn't ask a fish to climb a tree, why ask your wheels to do what they don't do best either?
The 56mm/86a Ricta Chrome Clouds are the not as soft as the 78a can still take it to skatepark, but really great on ditches wheel you need to tackle the rougher pavement ditches or DIY tend to offer.