keyway 204 c extending along the length of the bottom rail 204 the bottom rail 204 can be wider than the base element 202 and the bottom rail 204 and base element 202 can be coupled to one another to form an elongate bottom crossbar having a generally t shaped cross sectional profile the bottom rail 204 can be coupled to the base element 202 using various adhesives or mechanical fasteners the elongate bottom crossbar may be pre assembled or coupled together prior to receipt by an end user although a two piece bottom crossbar is shown a single unitary bottom crossbar having the same or different cross sectional profile may be provided in some embodiments the first end vertical key 202 a can have dimensions matching those of the first end vertical key 204 a and the second end vertical key 202 b can have dimensions matching those of the second end vertical key 204 b such that when the bottom rail 204 is coupled to the base element 202 the first end vertical keys 202 a 204 a have matching profiles and form a single vertical key that can engage with a corresponding keyway and the second end vertical keys 202 b 204 b have matching profiles and form a single vertical key that can engage with a corresponding keyway with continued reference to fig2 the first side element or post 206 includes a first end having a planar face or surface such that it can bear against and be secured to a fence post.