Spec to spec, both plastic deer fence materials are great for home growers: They both last between 10-20 years; contain certified breaking strengths from 650-1400 pounds; and are approximately 1.77" x 1.97" in diameter. While not chew-resistant like metal deer fence, these fences are ideal for gardens with light to moderate deer pressure.

If they are so similar, then what makes them unique?

The difference between Trident Plastic Fence and TENAX Plastic Fence is at the bottom. Trident Fence contains two horizontal strands at the bottom that offer additional ground support for holding down ground stakes and a barrier for browsing deer. 

The reinforced bottom edge is what makes Trident Extruded Fence a best selling plastic deer fence.