A standard full head of extensions for thin hair is 100-150 grams, this is totally safe when the weight is evenly distributed allover the head in separate pieces or strands. As the Supreme quad concentrates 120 grams onto one single strip it is not evenly spread throughout the hair, on thin hair this would be too much weight in one place. As the seam is bigger to hold the extra hair it would also be quite tricky to hide the attachment in finer hair types. For this reason the Supreme Quad is best for medium to thick hair types.