Basically it's a sequence of tabata workouts for a total of 12 minutes of work (you rest after you finish each one). (thebettyrocker.com)
Check out A 4 - Minute Tabata Workout for People Who Have No Time (health.com)
I cycle every month, one month a 5 × 5 strength cycle (heavy weight) next month doing tabata workout with weight to improve performance and muscle endurance. (nerdfitness.com)