Description WOI Top Mount Base Number 45, Top Mount Aluminum Bases Each base is machined to tight tolerances for a custom fit. Aluminum bases offer maximum strength for rings to hold tight. Firearms, trailers, and some accessories are only available for purchase in stores. Each location follows all BATF and individual state/county/city laws to insure the desired product is legal for sale. Any info provided online is subject to change, please go to your local store for more accurate information.