P90X2 - X2 Shoulders + Arms(2013)

Shoulder instability can lead to an assortment of injuries as we age. By keeping our shoulders and arms strong an din balance, we can avoid breakdowns. And that - along with looking good in short-sleeved shirts - is the philosophy behind the creation of X2 Shoulders + Arms. Keep shoulders and arms strong and in balance. And look great in sleeveless shirts.