Nu-Sleeve HV565 is highly resistant to end fray and coating fracture, even when stretched over rectangular conductors or wires larger than the normal maximum inside diameter, making it an ideal choice for high stress applications. - Nu-Sleeve HV565 is a heavy wall coated fiberglass sleeving made by extruding liquid silicone over a fully annealed fiberglass substrate, making it extremely resistant to abrasion with a high heat/flex capacity.