The 4" Stackable Wooden Plyometric Box is designed to build strength while using your body weight. This fundamental training box is constructed from high-quality plywood interlocking puzzle joints with a weight capacity of 400 LB. Specially crafted with a black textured non-slip surface, the durable, grippy texture reduces slipping and keeps the box in position on the floor. This step-up stackable box combines with the 6", 8", 12", or 16" options, configuring into 21 different stackable heights from 4" to 42" in 2-inch increments, plus a max height of 46" when all five boxes are stacked together. Challenge your daily routine with thousands of box jump variations, plyometric push-ups, or step-ups at any height for a full range of upper and lower body strengthening exercises.