Loctite 4205 prism gel is a clear, thermally resistant, rubber toughened, high viscosity instant adhesive for OEM assembly. It cures at room temperature and has excellent hot strength and heat aging properties. Suitable for porous surfaces and vertical or overhead applications. Adhesive for fiber optic components. - Loctite 4205 is a general purpose adhesive suitable for applications where heat resistance is required. Loctite 4205 is toughened with elastomers for flexibility, impact resistance and improved resistance to heat and humidity.