Product Composition:T-back Material:polyester Size Type:M/L/XL M: Weight:55-65KG(121-143LB) L: Weight:65-75KG(143-165LB)  XL: Weight:75-85KG(165-187LB) Ring diameter:3.3CM(1.3") Color Available:yellow/green/black Note:  1.Due to the difference between different monitors,...