Springless trampolines offer an alternative to the standard, spring-based trampoline. Rather than have a frame around the edge, with springs attached to the interior mat, spring-less trampolines use a unique construction with the frame below the mat fabric. Because there are no springs, users can jump on the mat all the way to the edge without risk of injury. However, springless trampolines are significantly more expensive than their spring counterparts. If safety is a large concern for you, they may be worth looking into.