Two of my Taekwondo and kettlebell students trying double kettlebell swings for the first time. A two hand kettlebell swing is two hand on one bell. A double kettlebell swing is two bells, one in each hand.
Here they are trying the combination of double swings and the front kick.
http://www.dragongym.com/adult-martial-arts/ — at Dragon Gym Martial Arts and Fitness.