The GS-890 is still designed for mounting antennas, lights or flag poles on the top of your t-top but with a longer body to accommodate thicker-tops. The GS-890 installs easily to compatible Taco Marine mounting plates. Their key features are in the location and that they can be actuated from the helm. This represents a significant convenience for boaters and a safety feature as well with the capability of adjusting from under the top. The rugged design will provide years of reliable service even in the most challenging saltwater applications. The GS880 & GS-890 are the ultimate solutions for boats 25'+ where safety is paramount.