First a bit of a whinge. Too many things I buy are poorly made or have incomprehensible or laughable instructions. In contrast I could not fault this door bolt. It has clear instructions with excellent diagrams. It comes with a range of fasteners and bits and pieces to enable it to be used easily in different positions on timber and aluminium doors, both sliding and hinged. It is not cheap at about $25 from Mitre 10 and Bunnings but it was well worth it to me.