1.best seller chest expander 2.Durable,strong,safety 3. Non-toxic,eco ... ,different size are acceptable.Nature rubber for human exercise-good for chest and back,durable,strong,good touch,soft,comfortable, ... portable,safe and environmental.Lifecycle:it can pull at least ... .Certificate:CE,ROHS,REACH,MSDS,PAHS and EN71. Chest Expander