Round base magnets is powerful,low profile magnets with a hole on center. Round Base Magnets is powerful,low-profile magnets with a hole on center.attach a hook or knob to position or hold inspection equipment,indicator gauges,lamp,signs,antennas and more.magnets are on side,and all around magnet are nickel or nickel/chrome plated for durability.We have many size for choose:RB-50,RB-60,RB-80,RB- ...