CHINESTONE have factory producing kinds of Granite and  Marble Stone Step/ Tread/ Staricase/ Riser/ Windowsills. etc.

110/120/130/140/150 x 30/ 33 /35 x 2 / 3cm with front  polished/bullnose edge

Note: Some customer require the top surface of step with  anti-slip lines (flamed or sandblasted)

Risers: Standard Size: 110/120/130/140/150 x 14 / 15  x 2 cm, top polished only

Windowsills: 120/150/180/220x30/35x3cm/4cm,etc. as per  customized sizes.

http://www.chinestone.com/