No predrilling required. Use in wallboard or plaster to fasten mirrors, pictures, bathroom fixtures, curtains, etc. 2-pieces per package. PackageTypeDescription ---- 1. This product is imported from overseas, so even if it is new, there may be some damage to the package, please rest assured that this does not affect the product itself. 2. Product warranty and other products made in Japan are not applicable. 3. Packaging and instructions are in English.