Shinwa Sokutei Basic 35mm Plasterboard Detector with 79025 Magnet,

When installing curtain rails, shelves, picture frames, handrails, earthquake-resistant brackets, etc., you can reliably find studs behind the wall. It has a scale so you can check the approximate thickness of the wall you have inserted. It comes with a magnet so you can easily find the metal behind the wall. Needle: Can be used in walls up to 35mm thick. Magnet: Can be used in walls up to 13mm thick and ceilings up to 12mm thick. *When searching for iron materials behind plasterboard, the range in which the magnet can be used will vary depending on the conditions. This is a needle-type base finder designed specifically for plasterboard. It cannot be used on reinforced plaster. If you feel any resistance in the base after inserting the needle, do not push it any further. The needle may break or bend, or it may remain stuck in the base wall when you try to pull it out, damaging the needle holder.