... . CE certificates 4. ISO9001 managenent system G603 granite L-shaped stairs, Granite L-shaped steps, Natural stone anti-slip steps 1. This ... L-shaped stair is glued by 3cm thick tread and riser. With ... 30 x 15 cm, thickness =3cm regular size for L-shaped stairs: 100~170 x 30/33 x 15-18cm, thickness ...