2 installation methods, 1) 3M Tape Double-Sided Self Adhesive, no need to drill,2) Screw In; our installation methods make sure that our Door Stoppers can be used on any surface of the wall, guarding your tile, glass, cement, wood, fiberglass, any smooth or rough surface from doorknob,furniture or cabinet impacts. Note: 3M double-sided adhesive tape should be left standing for 24 hours before use for better effect. Installment both reliable, Tape ,we choose 3M, Strong adhesive; Screw, compare to others, we add a screw, triangle supporting is more stable, both of the installing mothods have a long service life, its hanging weight can be up to 10 lbs, never fall off, protect your wall for ever. you can install it on the wall, to keep the door open, or install it on the door, then do not need to damage the wall Set of 2 included in your package, Multi colors can be chose, 3 Inches in height, Constructed of Stainless Steel, will not rust, and ensuring durability and dependability. Very