You need 8 wheels for a pair of roller skates (2 x 4 packs or 1 x 8 pack)

Sonar Stratus Features:

 

The Sonar Stratus is an entry level park skating wheel at a nice price. It offers better park performance than soft outdoor wheels and better park durability than harder indoor wheels. Sold in packs of four wheels. To order a full set of wheels, be sure to set your quantity to two.