This listing contains a single 78A Durometer replacement Inline Wheel which is designed for Roller Hockey use. These wheels are perfect for indoor skating, and utilize the standard size 608 bearing hub. If you only wish to use your wheels on outdoor skates, you should look for wheels with a harder duromer (80A or higher). Listing Includes: Qty x1 Wheel, Measuring 80mm in Diameter and 78A in Hardness.