PU CLEAR NILS EXTREME wheels are made of polyurethane. The most important wheel parameters are hardness and diameter. Wheel hardness determines both ride comfort and grip. PU-82A wheels provide good shock absorption and excellent adaptation to any surface. Wheel diameter directly affects riding speed. Larger diameter wheels allow for higher speeds, but do not guarantee as much maneuverability as smaller diameter wheels. Specification: Hardness: 82A Packaging: blister Quantity in package: 4 pcs. Size: PU 72×24mm/82A Comments: Not intended for commercial use 24-month warranty;PU MILKY WHITE NILS EXTREME wheels are made of polyurethane. The most important wheel parameters are hardness and diameter. Wheel hardness determines both ride comfort and grip. PU-82A wheels provide good shock absorption and excellent adaptation to any surface. Wheel diameter directly affects ride speed. Larger diameter wheels allow for higher speeds, but do not guarantee as much maneuverability as smaller diameter wheels. Specification: Hardness: 82A Packaging: blister Quantity in package: 4 pcs. Size: PU 72×24mm/82A Comments: Not intended for commercial use 24-month warranty