652D low water peak single-mode optical fiber, suitable for Beijing Dacheng Yongsheng Technology Co. 's fiber optic patch cords, fiber optic cables, and distributed fiber optic sensors. Product. This product is a standard G. 652D for metropolitan/access networks with low-water-peak performance (1260–1625 nm), or G. Loose Tube Thermoplastic Material (Polypropylene) Fiber Reinforced Plastic (FRP) to provide tensile strength and antibuckling properties Polyethylene Black Water swellable Yarns is added to prevent water. G. 652 is an international standard that describes the geometrical, mechanical, and transmission attributes of a single-mode optical fibre and cable, developed by the Standardization Sector of the International Telecommunication Union (ITU-T) that specifies the most popular type of single-mode.