This provides a firmer base than standard crash mat foam and is more stable when landing on it (when you land feet first on a crash mat there is a risk of ankle "roll over" like landing on an uneven surface where you can easily sprain or break an ankle). There are also 50mm wide velcro tabs on all 4 sides so the mats can be joined to create a larger landing area (with the tabs on the top side so feet don't go in between the mats). We recommend the mats extend 2m from the climbing wall.