Amazon.com: Keen Ramps - Skateboard Grind Box - 4ft or 6ft Long - Skate Grind Box for Skateboards, BMX Bikes, Scooters, & Roller Blades - Professional Skateboarding Ramps for Home - Made
Grind Box – My Broken Skateboard
South Bay Skate Co - Skateboard Grind box - 4' & 6' Box Lengths – South Bay Board Co.
DIY-Grind-Box-For-Skateboarding | Skate The States