POWER SYSTEMS BRAND. Improve your speed, strength and overall fitness with this new comfortable form fitting vest. Add resistance to your bodyweight training, jogging, jumping or other fitness activities without hindering the range of motions! The breathable design offers adjustable quick release buckles, reflective stripes and a secure pocket for your phone or mp3 player.One size fits most. Available in 6 and 10 lbs. model. Do not machine wash or soak in water.