Sector 9 Longboard Wheels TS Nineball 61mm - WHITE - Nineball Skateboard Wheels by Sector 9 offers size, strength, stability. 61mm, 78a durometer sold in sets of 4. Great for Longboards. These skateboard wheels are for bombing hills and going fast!!! Features - COLOR: WHITE - Size: 61mm - DUROMETER: 78A - Bearings and spacers not included. - Sold in sets of 4 - Long-lasting - Won't chunk out - Good for pools, parks, hills, and shredding concrete.