The Labeda Millennium Signature Wheel is an indoor roller hockey wheel available in 80mm, 76mm, 72mm, 68mm and 59mm. Made at X-Soft / 74a and Soft 76a (See other product) hardness and using Labeda's Flex core for a very grippy wheel. Made in the USA, the Millennium is best used on Sport Court / Tile Surfaces. Details: Best used: Indoor Surfaces Colour: White, Green, Purple, Yellow Wheel Sizes: 80mm, 76mm, 72mm, 68mm, 59mm Wheel Hardness: 74A - X-Soft - Softest wheel for lighter skaters Hub Size: Standard (608) Recommendation: Surface Info: Labeda can only recommend that you use these wheels on Plastic Tile / Sport Court surfaces. From experience we know they will perform great on smooth or painted concrete as well, but the concrete puts a beating on them. Using wheels off of a recommended surface would be at the skaters risk and not covered by warranty.