I purchased this new, but I'm selling it because I used it once and no longer need it. It was convenient with the magnet. ● This is a stud finder with needles for gypsum board. ● It can also find furring strips in ceilings. ● The needles can be used for walls up to 35mm thick. The magnet can be used for walls up to 13mm thick and ceilings up to 12mm thick. ● It detects wooden studs behind the board by piercing them with needles. ● You can easily and reliably find wall studs. ● The scale allows you to see the approximate thickness of the wall you've pierced. ● You can easily switch the lock with one hand, allowing for smooth operation. ● Two spare needles are included inside the main body. Shipping is planned via Yu-Packet.