Material:zinc alloy,steel,plastic Finish:white powder coated,satin-nickel For 8-12mm thickness door Material:zinc alloy,steel,plasticFinish:white powder coated,satin-nickelFor 8-12mm thickness doorThis kind of knob lock used for wood door,easy to install and use,with key,for more informatiion pls contact mr. Alvin via skype fsalvin or send us email. Knob lock for wood door