RAM Tough-Mag Heavy Duty Magnetic Mount with Round Plate - Medium attribute-uni-conn 7 is a die-cast aluminium

7 is a die-cast aluminium mirror arm

Diamond plate with the 2-hole AMPS pattern fits RAM® holders

Oregon® 450

No-drill Pod HD mount attaches via existing seat mounting bolts

How often should I replace them

RAM Tough-Mag Heavy Duty Magnetic Mount with Round Plate - Medium attribute-uni-conn 7 is a die-cast aluminiumRAM 101 MAG88U RAM Tough Mag Heavy Duty Magnetic Mount with Round Plate (Medium) The RAM 101 MAG88U is a complete heavy duty magnetic mount that clamps a device holder to any ferrous metal surface without drilling. It pairs an 88mm RAM Tough Mag base with a medium C size double socket arm and a 2. 5" round ball base, giving you extra reach and adjustment at both ends with a strong hold on steel. Key Features Magnetic or drill down mounting: 88mm Tough