Scopes of Application These expansion tubes are ideal for anchoring in concrete, brick or wallboard surface, can used for fixing curtains, calligraphy and painting, lamp, storage rack etc. Tough and Durable These expansion tubes are made from high quality plastic, which is of high toughness and durability. Anti-rust and anti-corrosive Due to the premium material, they are anti-rust and anti-corrosive also. Easy to use Just plug it into the pre-drilled hole, then screw up the screws.