Source 3 in 1 Jumping Gym Soft Foam Plyo Plyometric box 20/24/30" on m.alibaba.com
Philosophy Gym 12" Soft Foam Plyometric Box - Jumping Plyo Box for Training and Conditioning - Walmart.com
Amazon.com : Champion Sports Foam Plyometric Box Set with 3", 6", 12", 18", and 24" Included - Durable Jump Boxes for Training with Handles, Hook and Loop Flaps - Stackable Cross Traning