Brady's PermaSleeve™ heat shrinkable sleeves fit snugly around wires for maximum insulation protection and permanent identification. The full-circle insulating sleeves meet the rigid insulating material requirements and physical properties of MIL-DTL-23053/5 Class 1. MIL-M-81531. MIL-STD-202F. METHOD 215. and UL224 when printed with R5000 dot matrix and R4300 and R4502S (for black sleeves only) thermal transfer ribbons. These fade resistant. smudge-proof sleeves can be used with Brady's Sleeve & Datab™ Printers. as well as Thermal Transfer printers.