A silicone liner unit used for prosthetic limbs includes a silicone liner portion, a smooth outer layer, an inner layer and an innermost layer. The silicone liner portion is made of silicone elastomer liner and has an open end. The smooth outer layer is made of Hl a-methyl-Disilane or a compound containing poly-p-xylene and may have a slightly protrusive pattern on its outer surface. The inner layer is made of fibrous tissue and is flexible. The innermost layer is disposed on top of the inner layer and is made of silicone elastomer liner to enhance the strength of the improved silicone liner unit. The smooth outer layer allows the improved silicone liner unit to be put on and taken off easily.