MId-Rebound Plastic Polyurethane Durable and strong urethane will give you long-lasting grip whether on a rink, sidewalk, or street. | Fast precision ABEC-9 Bearing Fast rolling and high precision ABEC-9 Bearings. | Soft PU 78A Harness And Strong TPU Hub The soft PU allows these wheels to absorb the impact on the surface and roll over most small debris. A urethane hub that makes for a comfortable ride and offers excellent handling for trail skating. |