Dave & Cody 8ft Quarter Pipe Skateboard Ramp by OC Ramps – OmahaSportsAndGamesCompany
Amazon.com: OC Ramps Quarter Pipe (2' Tall x 3' Wide) - Durable Wood Skateboard Ramp Kit - Store Easily in the Garage - Great for Home or Professional Use and also Works
South Bay Skate Co - Quarter Pipe Skateboard Ramp - 2' Tall x 4' Wide - by Keen Ramps – South Bay Board Co.
Skateboard Ramps - 5 Minute Guide to Skate Ramp Varieties
HOW TO BUILD A D.I.Y QUARTER PIPE SKATE RAMP *easiest way* - YouTube