... ,welcome to contact with us. MaterialsNatural Stone (more materials availalbe: granite, marble, sandstone, travertine, limestone, etc.)Stair typeStraight stairs ,spiral ... stairs ,arc stairs Popular stone for steps granite:G603,G636,G664,G687,G654,G562,G682,G684,absolute black ... , sandblasted or customized.Usge Building ,garden ,etc Common sizes tread:110-150 x 30-33 x 2/3cm or customized ...