... total core, 4 springs, two head restback,with handle bar. plastic plug, rotation seat Key Specification-Materials: iron, PP, PVC,foam ... Description:1.Material compostion:steel,plastic or foam.2.Easy to use,no matter what fitness level.3.Four or Six iron ... .5CMWEIGHT: 7.0kgs/7.5KGS RED AD trainer, TOTAL CORE, plastic plug