Guantai Dia 2.5mm 40mm (Popular) Fiber Optic Fusion Splice Protector Protection Sleeves, Clear Heat Shrinkable Tube -1000pcs Clear sleeve make it easy to detect splice before shrinkage Easily use and avoid any damages to the optical fiber during installation Moisture resistant for environmental protection Consist of a rod of reinforcing the splice, heat fusion tubing and cross-linked polyolefin. To rebuild the coating of fiber to provide mechanical strength at the fusion joint area and keep optical transmission properties