ADJUSTABLE BASE DESIGN - We design these planter box brackets base with a slider bracket component which can adjust the length of base rail to fits all kinds of flower boxes with minimum 6'' and the maximum 12'' depth ( Front To Back) .STURDY & DURABLE - Our wall mounted flower box brackets are made of good-quality and extra thickness iron with Black powder-coated finish. The brackets are designed to holds weight up to 40 lbs.WIDE APPLICATION - The Anti-rust and Anti-corrosion design planter box brackets can be used both indoors or outdoors. The brackets are affixed individually on the wall or under window or bolted to the railings of a porch or deck and holding all kinds of planter box sturdy.