Material: polyester + latex silk Advantage: deep squat resistance takes pull force big, rebound flexibility is good, deep squat is the best action that raises leg ministry strength, still can promote systemic strength very well, the first selection that develops leg ministry muscle, promote systemic muscle growth, improve cardiac function. Squat down to strengthen your heart. Practice squats regularly to make your heart stronger. Size: Lake blue: 76*8cm 30~40LBS pink : 76*8cm 50-60LBS purple : 76*8cm 70-80LBS Package include： 3*squat resistance belt 1*Mesh bag 1*instructions