The RF energy penetrates the skin layers to selectively heat the skin tissue and the extra cellular matrix where the collagen fibres are embedded. The local heating causes an immediate contraction of collagen fibres, and at the same time increases the metabolism of the fibroblasts thereby accelerating the production of new collagen and elastin fibres. The concentration of collagen fibres and the regeneration of the collagen and elastin deposits, tighten the skin layers creating smoother, firmer and younger looking skin.