TAC SEPA: Stacked Box Agility Drill May 26, 2016ExercisesSSD The goal of this drill is train level changes, the functional agility of quickly scaling a low fence or other obstacle. We us staked plyo boxes as obstacles, but any scaleable obstacle will work. Others have used short fences, old cars, the beds of pickup trucks, etc. Box/Obstacle height is 48-60 Inches. The plates on the boxes in the clip help with stability. Clip only shows the drill being completed unloaded. It can also be completed in a weight vest/IBA.