Fishing Magnets Size: Powerful fishing magnets are 2.36 inches in diameter and have a maximum pull force of 400 lbs based on 1.18-inch-thick steel plate under ideal conditions. Good Corrosion Resistance: The magnet has three layers of protective coating - Ni (nickel) plus Cu (copper)plus Ni (nickel) and steel case protection it can be used underwater and other harsh environments (Max Working Temperature:80℃). Magnet Can lift 400LBS underwater. In addition the steel shell helps to prevent the bare magnetic from being scratched cracked or peeled off. The loss of magnetic performance doesn t exceed 2% within 10 years. Multi-purpose Use: Fishing magnets can be used for underwater treasure hunting salvaging and recycling metal items such as heavy metal items water pumps antiquities etc. It can also be a good helper for fishing you can retrieve lost bait or lose some things Industrially it s used in workshops to find and recover lost accessories such as screws washers nuts fasteners screwdrivers and other sporadic sundries. Packing List: The fishing magnet bag will have what you need. Diameter 5.0mm (0.196inch) x Length 20m (66 feet) Nylon high-strength rope a pair of non-slip gloves galvanized carabiner. Be fully prepared for your salvage activities.