RAINBOW 3D COG 21G90-L This thread is designed to reshape and lift the skin surface. Inserting the PDO thread under the skin creates a wound-healing effect, regenerates skin cells, and stimulates the body’s own collagen production, which provides an ideal volume and firming effect immediately after the treatment. It is used for skin tightening because it stimulates natural collagen production and restores lost volume. Mainly used for areas like Jaw, midface, and eyebrows.