General?s Pickup and Release Magnets will help you lift cumbersome iron and ferrous metal parts weighing up to 16 lbs. They can be used to clean up scrap metal around the base of a milling machine or to separate screws and staples from a pile of debris. Pickup and Release Magnets are also great on construction sites for grabbing fresh nails out of a pail, which can be hazardous if done by hand. This item features a 4? diameter magnetic surface and a one-handed on/off operation.