Guest Super Dynaplate f/SSB Radio - 18" x 6" x 1/2". SSB and AM radio transmitters rely upon a proper size ground to operate to their designed capacity. A Dynaplate grounding shoe helps provide a large solid surface (the water surrounding the boat) to "push off" from. This is technically known as "counterpoise" and is the other necessary half of the antenna system. The bronze Dynaplate material also serves as the next sacrificial metal on the galvanic scale after the zincs providing another buffer against corrosion of stainless steel parts. Specifications for Guest Super Dynaplate f/SSB Radio: Manufacturer: Guest Color: Black Features of Guest Super Dynaplate f/SSB Radio Easy to clean with wire brush Conforms to ABYC standards Mounting hardware included Gold plated mounting bolt Bronze mounting nuts Copper washers Package Contents: Guest Super Dynaplate f/SSB Radio Guest 4018: Super Dynaplate f/SSB Radio - 18" x 6" x 1/2"