Bottom shaft: Medium carbon steel shaft is strengthened and heat treated, roughness PU cushion: 95A ultra-high rebound polyurethane, high elasticity The bridges has four holes inside and four holes outside, suitable for most of skateboard Actual color may be slightly different from the image due to different monitor and light effectPlease allow 1-3cm deviation due to manual measurementAsian size is smaller than eu/us/uk size,please compare the detail sizes with yours before purchasing. Panel classification: double rocker Material:Aluminum-magnesiums alloy Size:20cm(width)Color:silver/black Included: 1x Bracket