The Gill 640A Essentials high jump landing system is a great value for your track and field program. The select density gray polyurethane foam offers superior resistance to UV deterioration and a comfortable cushion for your athletes to fall into. 18 oz. vinyl coated woven polyester is very durable and puncture resistant. Unlike vinyl-coated nylon, which can expand and contract over 12%, this fabric holds its shape under the worst conditions. All section seams are heat sealed for water resistance. Avionic Velcro grade hook and loop material exceeds grip requirements even after 5000 assembly cycles.The weather and ground covers use the same super strong vinyl coated woven polyester as used in the pit casings with top and bottom heat-sealed seams to keep moisture out. The top of the base unit is made of a vinyl coated woven polyester mesh for superior strength. This mesh top allows for the air to escape, which provides for optimal landing compression. The extra heavy #138 nylon thread is used for the seams throughout the entire landing system and the seams are folded and triple stitched increase strength and provide water resistance. The D-ring straps are back stitched for added holding power.Zinc plated snap-hooks and stainless steel D-rings ensure placement for the top pad and the heavy-duty plastic zippers are corrosion resistant for smooth operation in all conditions. The top pad is made of a 2" foam that is encased in vinyl coated woven polyester mesh fabric and covers the entire surface.The overall design of the Gill 640A Essentials is truly remarkable. The carrying handles are double box "X" stitched with heat sealed reinforcement behind the stitching and are made from a one-piece Velcro fastening system that are easy to secure; once fastened it will not slip or break loose. The base of this landing system is interchangeable for more even wear and longer life. Each base consists of a foam cross tunnel construction that facilitates a smoother landing.